Sarah Kieffer began her professional baking career at coffee shops in Winona, Minn., and the Twin Cities, a livelihood that eventually led this former English major to blogging, which in turn created a 2016 cookbook, "The Vanilla Bean Baking Book."

A different level of fame struck in 2017, when the New York Times published Kieffer's "pan-banging" technique for making chocolate chip cookies. The buttery, wrinkled cookies had gone viral on Instagram, and then the Times catapulted the recipe into a baking sensation.

Kieffer has capitalized on that opportunity by expanding the pan-banging formula into a dozen iterations in her just-released "100 Cookies: The Baking Book for Every Kitchen" (Chronicle Books, $27.50), which includes 88 other gotta-bake cookie and bar ideas.

In a recent phone conversation, Kieffer, who also shoots the photos in her books, discussed the sources of her inspiration, her favorite baking tools and the power of Instagram.

Q: Why the focus on cookies?

A: I'd written a proposal for a different book. Then my cookie was in the New York Times, and a lot of people loved it. That's when my agent suggested, "What if you do cookies?"

Q: Was it a challenge to come up with 100 recipes, or was it more difficult to whittle down your roster to that number?

A: Both. I had all of these ideas, but it's hard getting 100 recipes to be great, due to all the time that goes into testing. But I still ended up having a lot of extra recipes, and so I prepared a free e-book for people who preordered the book. People have been baking out of it and posting on Instagram, and that's been really fun.

Q: On the subject of Instagram, what role has that platform played in your success?

A: A big one. It helped the New York Times find my recipe, and I'm grateful for it. I still go there for inspiration, and I try to post a couple of times a week.

Q: You have 166,000 followers on Instagram. Do you have any how-to-Instagram wisdom that you'd care to share?

A: I played around a lot when I first started, trying to find my style. I've found that what works for me is focusing on the food, and not on the props, or the background. I've kept my style consistent, that's important for me. I started my blog eight years ago, and so much has changed in food media over those last eight years.

Q: On the eternal "Are bars cookies?" question, you land in the affirmative camp. Why?

A: Well I am from Minnesota, and I just said that with a great Minnesota accent [laughs]. When I was growing up, they were interchangeable — you slap cookie dough into a pan, and you have bars — and they've been interchangeable in every coffee shop where I worked.

Q: What was the genesis of that great-looking "Neapolitan" cookie?

A: I'd seen them on Pinterest. They're the work of pastry chef Matthew Rice. They're so pretty, and I decided to have a go at them, using my own sugar cookie recipe. In his recipe, he uses Nesquik strawberry milk powder, and I use freeze-dried strawberries. There are so many freeze-dried flavors that you can use, and make all kinds of cookies. My kids still ask to make them, weekly, and they're fun to make. My husband is so kind and helpful. He cleans up after me, but the sprinkles in this recipe drive him crazy. They end up everywhere.

Q: Is there a baking tool that you absolutely could not live without?

A: Probably my stand mixer, because it just makes everything so much easier. I'd be sad without it. I also rely upon good baking pans. I really love Nordic Ware's half-sheet pans. They're the perfect weight, and they're the only baking pans I have in my kitchen.

Q: When you're in recipe testing mode, what does your grocery cart look like?

A: It's insane. I still get panicky if I don't have at least four pounds of butter in the refrigerator at all times.

Q: You're the rare cookbook author who also shoots her own images. Where do you take your beautiful food photos?

A: I have a three-season porch on the back of my house, and I pretty much shoot everything there, on a table with a marble top. The conditions are not ideal. It's perfect for two months of the year, otherwise it's boiling hot or below zero. But the light is really nice. It's basically all windows.

Q: Where do you turn for inspiration?

A: I do social media for Zoë François and Jeff Hertzberg [the Twin Cities partnership behind the "Artisan Bread in Five Minutes a Day" cookbook phenomenon], and I did the how-to photographs for their new book. Zoë is a great friend, and she's taught me so much, even by just watching her at work. She's always so helpful and kind, and her Instagram is amazing and inspiring.

Q: What's next for you?

A: I just finished a holiday baking book that's coming out next fall [2021].

Q: You were once a novice baker. What advice do you have for those just starting out?

A: The biggest thing is patience, and practice. You'll learn so much if you make a recipe over and over. Have lots of grace for yourself, and just have fun. People get so intimidated by baking. I want baking to be playful, and to come from a place of comfort and not fear. Cookies are a gateway into baking. They're usually easier than other recipes, and if you mess things up, it will still taste good.

Rick Nelson • @RickNelsonStrib.

Meet the author

What: "100 Cookies" author Sarah Kieffer will discuss her new book with "Artisan Bread in Five Minutes a Day" co-author Zoë François (

When: Aug. 27, 5 to 6 p.m.

Where: Live, on Zoom. Register at

Neapolitan Cookies

Makes about 20 cookies.

Note: "The powdered strawberries on their own won't give a bright pink hue, so I like to add a little food coloring. I also like to roll each individual color of dough in the same sprinkles, but you can mix and match however your heart desires," writes Sarah Kieffer in "100 Cookies." Find freeze-dried berries in the dried fruit aisle at the supermarket.

• 2 1/2 c. plus 1 tbsp. flour

• 3/4 tsp. baking soda

• 3/4 tsp. salt

• 1/2 c. freeze-dried strawberries

• 1 c. (2 sticks) unsalted butter, at room temperature

• 1 3/4 c. sugar

• 1 egg

• 1 egg yolk

• 2 tsp. vanilla extract

• 2 to 3 drops red food coloring, optional

• 2 tbsp. Dutch-process cocoa powder

• White, pink and brown sprinkles, optional


Adjust an oven rack to the middle of the oven. Preheat oven to 350 degrees and line baking sheets with parchment paper.

In a medium bowl, combine flour, baking soda and salt.

In the bowl of a food processor fitted with a metal blade, pulverize the strawberries into a powder.

In the bowl of an electric mixer on medium speed, beat the butter until creamy, about 1 minute. Add the sugar and beat until light and fluffy, 2 to 3 minutes. Add the egg, egg yolk and vanilla extract, and beat until combined. Reduce speed to low, add flour mixture and mix until just combined.

Dump the dough out onto a work surface and divide it into 3 equal portions. Put one-third of the dough back into the mixer and add the powdered strawberries (and food coloring, if using). Mix on low speed until totally combined, then remove the dough and wipe out the bowl. Add another one-third of the dough to the bowl. Add the cocoa powder and mix on low speed until totally combined.

Pinch a small portion (1 to 2 teaspoons) of each of the three doughs, and press them gently together, so they adhere to each other, but keep their unique colors. Form the dough into a ball, then roll the ball into sprinkles (if using). Place 6 or 7 cookies on a prepared baking sheet. Bake the cookies 1 baking sheet at a time, rotating halfway through baking. Bake until the sides are set and the cookies are puffed, 10 to 11 minutes. Transfer the baking sheet to a wire rack and let the cookies cool for 5 to 10 minutes on the baking sheet, then remove them and let them cool completely on the wire rack.

Chocolate Hazelnut Bars

Makes 12 large or 24 small bars.

Note: Hazelnut flour is found in the baking aisle of many supermarkets, or can be prepared by finely pulsing skinned hazelnuts in a food processor. From "100 Cookies."

For chocolate filling:

• 2 (14-oz.) cans sweetened condensed milk

• 7 oz. semisweet chocolate, melted

• 2 tbsp. heavy cream

• 1 tsp. vanilla extract

• 1/2 tsp. salt

For hazelnut crust:

• 2 c. all-purpose flour

• 1 1/2 c. hazelnut flour (see Note)

• 1/2 c. brown sugar

• 1/4 c. granulated sugar

• 1/2 tsp. baking soda

• 1/2 tsp. salt

• 1 c. (2 sticks) unsalted butter (sliced into 1-inch pieces), at room temperature, plus extra for pan


To prepare chocolate filling: In a large bowl, whisk together the sweetened condensed milk, chocolate, cream, vanilla extract and 1/2 teaspoon salt until smooth.

To prepare hazelnut crust: Adjust an oven rack to the middle of the oven. Preheat oven to 350 degrees. Grease a 9- by 13-inch baking pan and line the bottom and sides with crisscross pieces of parchment paper.

In a bowl of an electric mixer on low speed, combine all-purpose flour, hazelnut flour, brown sugar, granulated sugar, baking soda and 1/2 teaspoon salt. Increase speed to medium, add the butter; mix until crumbly.

To assemble: Press half the crust mixture into the bottom of the prepared baking pan and bake for 10 minutes. Remove the pan from the oven and carefully spread the chocolate filling over the crust. Sprinkle the remaining half of the crust mixture evenly over the top. Return pan to oven and bake until the chocolate has puffed up a bit and does not jiggle, and the crumbly top is light golden brown, about 15 to 20 minutes.

Remove from oven and transfer the pan to a wire rack and let cool. Place the pan in the refrigerator and chill for at least 6 hours. Slice the bars and serve. The bars can be served cold or at room temperature, but keep best in an airtight container in the refrigerator for up to 3 days.