Ingredients
Cookies:
6 oz unbleached all purpose flour
1/2 teaspoon table salt
1/2 teaspoon baking powder
1/4 teaspoon baking soda
4 oz (1/2 cup) unsalted butter
1 1/3 cups granulated sugar
1 1/5 oz unsweetened coco powder
3 large eggs
3/4 teaspoon vanilla extract
3 oz bittersweet chocolate, melted and slightly cooled
Filling:
3 oz bittersweet chocolate coarsely chopped
2 oz (4 tablespoons) unsalted butter, cut into 3 pieces
Preparation
Make the cookies:
Position a rack in the center of the oven and heat the oven to 350 degrees. Line 3 cookie sheets with parchment or non stick baking liners.
In medium bowl, whisk flour, salt, baking powder and baking soda.
In a stand mixer fitted with paddle attachment, beat butter, sugar and coco powder on medium speed until well blended, 5 minutes. Scrape down the beater, add vanilla. Add the eggs 1 at a time, mixing until blended after each addition, about 30 seconds. Continue mixing on medium speed until well blended, 1 minute. Add the cooled melted chocolate, mix until just blended. Add flour mixture mixing on low speed until just blended.
Using a 1 tablespoon scoop, drop dough about 1 1/2 inches apart on the prepared cookie sheets. Bake one sheet at a time, until the cookies are puffed and the tops are cracked and look dry. 11-13 minutes.
When the cookies are out of the oven, use the rounded side of a 1/2 teaspoon measure to make a small deep well in the center of each cookie. Let cookies cook on cookie sheet for 5 minutes. Transfer to a rack.
Filling:
Melt the chocolate and butter in a medium bowl set above a pan of simmering water. Remove from heat, let cool.
Spoon the chocolate mixture into the wells of the cooled cookies.
Store in an airtight container for up to 3 days.
