Espresso Chocolate Chip Bars

Crust
2 cups flour
1/2 cup powdered sugar
1/8 tsp salt
8 ounces (2 sticks) cold butter, cut into 1/4-inch pieces
1-1/2 tsp vanilla extract

Topping
4 ounces (1 stick) butter, at room temperature
3/4 cup packed light brown sugar
2 eggs
1/4 cup milk
1 tsp vanilla extract
1 cup flour
1 Tbsp instant espresso coffee powder or 2 Tbsp finely ground espresso coffee
2 Tbsp unsweetened cocoa powder
1/8 tsp salt
1 cup chocolate chips

1. To prepare the crust: Combine the flour, powdered sugar, salt, butter and vanilla in a food processor. Process until the dough forms a ball. Press evenly into the bottom and halfway up the sides of a 9x13-inch baking pan. Bake in a preheated 350-degree oven 20 to 25 minutes, until the edges just start to turn golden. Transfer to a wire rack and cool in the pan about 30 minutes. Keep oven at 350 degrees.

2. To prepare the topping: Beat the butter and sugar together in an electric mixer until fluffy. Add the eggs, milk, vanilla, flour, espresso powder, cocoa and salt. Stir in the chocolate chips.

3. Transfer the mixture to the cooled crust, spreading evenly with a thin spatula. Bake in the preheated oven 25 minutes. Cool on a rack before cutting.

Makes 36 pieces.

From "Espresso, From Bean to Cup"