- 1/2 cup (1 stick) unsalted butter, plus more for pan
- 4 ounces unsweetened chocolate, chopped
- 1 1/2 cups sugar
- 1 tablespoon instant espresso powder
- 2 teaspoons pure vanilla extract
- 4 large eggs, lightly beaten
- 1 cup all-purpose flour
- 3/4 teaspoon ground cinnamon
- 1/2 teaspoon ground nutmeg
- 1/4 teaspoon salt
- 3/4 cup semisweet chocolate chips
Preheat oven to 325 degrees.place rack in center. Butter a 9-inch square baking pan, and line the bottom with parchment or wax paper. Coat paper with butter; set aside.
In a large saucepan over very low heat, melt chocolate and butter together, stirring, until completely melted. Let cool slightly. Whisk in sugar, espresso powder, vanilla, and eggs.
In a medium bowl, whisk together flour, cinnamon, nutmeg, and salt. Add to the chocolate mixture, and stir until just combined, but do not overmix. Fold in chocolate chips.
Pour into prepared pan, and bake until a toothpick inserted in the center comes out slightly wet, 30 to 35 minutes. Transfer to a wire rack; cool completely. Run a sharp paring knife around edges, then invert. Peel off parchment paper, and cut into 16 squares.