Thin Mocha Chocolate-Chocolate Chip Cookies with Mocha Cream Filling
2 cup all purpose flour
4 tablespoons unsweetened cocoa powder
2 tablespoons unsweetened dark cocoa powder
2 teaspoon baking soda
1 teaspoon salt
2 sticks unsalted butter, room temperature
1 1/2 cup (packed) golden brown sugar
1/2 cup sugar
2 large egg
1/4 cup water
2 teaspoon vanilla extract (or mint, yum!)
2 teaspoon instant coffee granules
1 cups semisweet chocolate chips
1 cup milk chocolate, coarsely chopped
1/2 cup semisweet chocolate chips
1/2 cup whipping cream
1 tablespoons instant coffee granules
1 cups powdered sugar
1 sticks unsalted butter, room temperature
1 teaspoon vanilla extract
Stir chocolate chips, cream, and coffee granules in heavy saucepan over medium heat until chocolate melts and coffee dissolves. Cool to room temperature, about 20 minutes. Using electric mixer, beat sugar, butter, and vanilla in bowl until blended. Beat in chocolate mixture. Refrigerate until beginning to firm, about 20 minutes.
Preheat oven to 325F. Line 2 baking sheets with parchment paper. Sift flour, cocoa, baking soda, and salt into bowl. Using electric mixer, beat butter and both sugars in bowl until well blended. Add egg, 4 teaspoons water, vanilla, and instant coffee; blend well. Beat in flour mixture. Stir in chocolate chips and chopped chocolate. Drop dough by tablespoonfuls onto prepared sheets, spacing 2 inches apart. Bake until tops are just firm to touch and no longer shiny, about 10 minutes. Cool cookies on sheets 10 minutes. Transfer to racks and cool.
Once the cookies are room temperature, place cookies flat side up on work surface. Spread each with 1 tablespoon of buttercream leaving 1/4-inch border. Top each with second cookie, pressing to adhere. Cover and chill at least 2 hours. (Can be made 2 days ahead. Keep chilled.) Cookies are best served cold.