Active Time

　　20 min

　　Total Time

　　1 1/4 hr

　　

Ingredients

Makes 32 (2-inch) squares

　　2 sticks (1/2 pound) unsalted butter

　　5 ounces unsweetened chocolate

　　2 tablespoons instant-espresso powder

　　2 cups sugar

　　1 teaspoon pure vanilla extract

　　5 large eggs

　　1 cup all-purpose flour

　　1 tablespoon cinnamon

　　1/2 teaspoon salt

　　

Step 1

Preheat oven to 350°F with rack in middle. Butter and flour a 13- by 9-inch baking pan.

　　

Step 2

Melt butter and chocolate with espresso powder in a 3-quart heavy saucepan over low heat, whisking until smooth. Remove from heat and cool to lukewarm. Whisk in sugar and vanilla. Whisk in eggs 1 at a time until mixture is glossy and smooth.

　　

Step 3

Whisk together flour, cinnamon, and salt, then whisk into chocolate mixture.

　　

Step 4

Spread batter in pan and bake until a wooden pick inserted in center comes out with crumbs adhering, 25 to 30 minutes. Cool completely before cutting.