The cake-like chocolate cookie for this ice cream sandwich was inspired by a recipe from Cook’s Illustrated, except I didn’t want to use the canned chocolate syrup they suggested so I manipulated the recipe to prevent that need.
Also, baking one time their recipe didn’t produce a thick enough cookie for my taste. The next time I doubled the cookie recipe, which was then too thick. For the third test, I made it 1 1/3 times the amount which was too thin. Therefore, I landed on 1 1/2 times the recipe which is what is listed below.
Also the original recipe had the cookies cut into rounds. That seemed like too much waste, so I cut mine into squares and filled them with a no-churn toasted coconut ice cream.
12 tablespoons (6 oz / 170 g) unsalted butter, cut into pieces
4 ½ oz (128 g) bittersweet chocolate, chopped
½ teaspoon Kosher salt
1 teaspoon water
1 teaspoon pure vanilla extract
1 ½ cups (7 ½ oz / 215 g) unbleached all-purpose flour
¾ cup (2 ¼ oz / 60 g) Dutch-processed cocoa powder
¼ teaspoon baking soda
3 large eggs, room temperature
1 cup (7 oz / 200 g) granulated sugar
Preheat oven to 350 degrees F. Butter a 12 x 17-inch jelly roll pan. Line with parchment paper. (There’s no need to butter the paper.) Set aside.
Melt butter and chocolate in a medium bowl over a pan of barely simmering water (aka ban-marie or hot water bath). Remove from heat and stir in salt, water, and vanilla extract. Set aside.
While chocolate/butter mixture is melting, set a seive over a medium bowl and sift together flour, cocoa powder, and baking soda. Set aside.
In a large bowl whisk together eggs and sugar. Whisk in melted chocolate/butter mixture. Using a large rubber spatula fold in dry ingredients.
Using a large offset spatula spread batter evenly in prepared pan. Place on lower third of the pre-heated oven and bake for 10 – 14 minutes, or until the cookie springs back when lightly touched with your finger.
Remove from the oven and allow to cool completely. Cut around the edges of the pan to loosen the cookie. Set another sheet pan on top and flip over to release it. Divide cookie into two pieces.
Slice your favorite ice cream into ¼-inch slices and line one half of the cookie with the slices. (See Toasted Coconut Ice Cream recipe .) Set the other half of the cookie on top and cut the “sandwich” into 16 squares. Return them to the parchment lined sheet pan to refreeze. Remove from the freezer and wrap each in waxed paper and then in aluminum foil. Return to the freezer but serve within a week.