While there is no day that isn't improved by eating a brownie, something about a summer day makes brownies taste even better.

Maybe it's because they travel well to picnics. Or because they're a perfect blank canvas for swirling in a whim of caramel, peanut butter, marshmallows and more.

Purists, though, may be happy to know that the basic brownie recipe actually has changed little since Fannie Farmer first came up with the bar cookie in 1906. Basically, it's a chocolate cake with a greatly reduced amount of flour.

Still, two brownie camps have emerged: cakey or fudgey, with the difference being the amount of flour in the recipe. Cookbook author Shirley Corriher, the foodie biochemist and author of "BakeWise"and "CookWise" cookbooks, says there's yet another division between those who like a shiny crust and those who don't. The delicate, crisp crust results from not only blending beaten eggs into melted chocolate, but vigorously beating them, creating a meringuey effect when baked. 

If you want more of a matte finish -- and a less brittle brownie -- don't beat, just blend, according to Corriher.

As far as adapting a recipe to be cakier or fudgier, the simplest fix may be increasing the number of eggs in the recipe, thereby reducing the proportion of flour in the batter. The accompanying recipe offers the best of both worlds, the brownies veering toward a cakey texture on the day they're baked, but settling into fudginess if left overnight, especially if refrigerated. To make them even lighter and cakier, increase the number of eggs from four to five. For gooier brownies, use only three eggs.

A few more tips for the best brownies ever:

• Alice Medrich, known for her recipes for all things chocolate, says that refrigerating the brownie batter overnight, in the pan and covered tightly, improves the flavor. She also often opts for bittersweet chocolate instead of the unsweetened chocolate called for in many recipes.

• For an even fudgier flavor, substitute brown sugar for white sugar, or go half-and-half.

• It's often difficult to tell when brownies are done, but it's always better to underbake than overbake them. Minnesota native Amy Scherber of Amy's Bread in New York City says that once the edges feel slightly firm, even though the center seems soft, the brownies are finished.

• Brownies are easier to cut when chilled, or at least cooled completely.

• Brownies are best eaten on a summer afternoon while on a blanket spread under a shade tree on a lakeshore. OK, that's not really a tip, because you already know that.

Kim Ode • 612-673-7185