Summer cookouts may beg for blueberry pie, but summer birthdays scream for ice cream cake.

The standard ice cream shop variety usually consists of chocolate and vanilla ice cream sandwiching a layer of addictive fudge crunch, but if you make ice cream cake at home, the flavor possibilities are limited only by your imagination. Coffee cream, peanut butter chocolate, cherry almond, banana split — your favorite flavor combination can be achieved in ice cream cake form if you follow this simple formula:

Cake + ice cream flavor A + something spreadable (like fudge, marshmallow cream or peanut butter) + something crunchy (like crushed cookies, graham crackers or nuts) + ice cream flavor B + stabilized whipped cream = ice cream cake.

The process is, well, a process. Each layer needs time to freeze before adding the next, but if you follow these basic tips, in the end you’ll have a decadent cake that you won’t find anywhere else.

Ingredients: Fill in the blanks of the formula above with your favorite flavors. Note that caramel will harden when frozen, so it’s not a good choice for the spreadable layer. I layered chocolate cake, vanilla ice cream, hot fudge, crushed chocolate cookies and caramel ice cream for Caramel Chocolate Crunch cake. I also tried yellow cake, chocolate ice cream, marshmallow cream, crushed graham crackers and rocky road ice cream for S’mores Cake.

Baking pan: The deeper the sides, the better. I used an 11-cup rectangular glass baking dish for one cake, and a 9-inch round cake pan for the other. The round pan wasn’t deep enough to keep the cake layer on the bottom when layering the ice cream, so I baked the cake, then pulled it out, layered and froze the ice cream in the dish and added the cake back to the top at the end before frosting. The rectangular dish was deeper, so I kept the cake layer on the bottom and layered the ice cream on top. That produced a different, less cakey texture, because the ice cream soaked into the cake a bit while freezing. I enjoyed that, but if you want an airier cake layer, put it on top.

Freezing time: Turn your freezer down to 0 degrees. Allow at least two hours for each layer of ice cream to freeze enough in order to spread the next layer. I let the cakes freeze overnight before removing them from the pan to frost, and that worked perfectly. Since it’s an all-afternoon affair, you’ll want to make this cake a day in advance, anyway.

Spreading the ice cream: Leave enough time to soften the ice cream for 20 to 30 minutes at room temperature before spreading. Stir the ice cream so the texture is consistent and spreadable, but not too runny, or it will take longer for it to refreeze.

Whipped cream: Regular whipped cream will become runny when it begins to thaw, so it’s best to stabilize your fresh whipped cream with gelatin before icing the cake and freezing it. If you’d rather ice the cake immediately before serving (and don’t plan on refreezing the leftovers), you can skip the addition of the gelatin, but it only takes an extra minute to stabilize the cream.

Appearance: If you want your cake to look pretty, first frost it with a thin layer of stabilized whipped cream — the equivalent of a crumb layer on a traditional cake — and freeze it for 15 minutes. Then add a thicker layer of whipped cream to cover it again and make it look nice. The frosting will stick better the second time, and you won’t have to worry about ice cream melting into the icing.

Time involved: It takes about 45 minutes to bake and cool the cake layer, then two hours to freeze the first layer of ice cream and at least two hours, but preferably overnight, to freeze the final layer of ice cream. Then you’ll need 15 minutes to freeze the first layer of frosting before finishing the cake. So although the process involves little active time, you’ll need at least 5 hours, but if you’re spreading it over two days, plan for 3 hours on Day 1 and 20 minutes on Day 2.