Prep 45 mins
Cook 30 mins
These are delicious! Recipe courtesy of The America's Test Kitchen Family Baking Book. You can use old-fashioned rolled oats, but the bars will be more chewy. Make sure you cool the crust before you add the filling.
Crust and Topping
- 1 cup quick-cooking oats
- 1 cup light brown sugar, packed
- 3⁄4 cup all-purpose flour
- 1⁄4 teaspoon baking powder
- 1⁄4 teaspoon baking soda
- 1⁄8 teaspoon salt
- 8 tablespoons unsalted butter, melted and cooled
- 1⁄4 cup all-purpose flour
- 1⁄4 cup light brown sugar, packed
- 2 teaspoons instant espresso or 2 teaspoons instant coffee
- 1⁄4 teaspoon salt
- 1 1⁄2 cups semi-sweet chocolate chips
- 2 tablespoons unsalted butter
- 1 large egg
- For the crust and topping: Adjust an oven rack to the middle position and heat the oven to 325 degrees. Line an 8 inch square baking pan with a foil sling and grease the foil.
- Whisk the oats, brown sugar, flour, baking powder, baking soda, and salt together in a large bowl.
- Stir in the melted butter until combined.
- Reserve 3/4 cup of the oat mixture for the topping.
- Sprinkle the remaining oat mixture into the prepared pan and press into an even layer with the bottom of a measuring cup.
- Bake the crust until light golden brown, about 8 minutes.
- Let the crust cool completely on a wire rack, about 1 hour.
- For the filling: Whisk the flour, sugar, instant espresso, and salt together in a medium bowl.
- Melt the chocolate chips and butter together in a microwave, stirring often, 1 to 3 minutes.
- Transfer the chocolate mixture to a large bowl and let cool slightly.
- Whisk in the egg until combined.
- Stir in the flour mixture until just incorporated.
- Adjust an oven rack to the middle position and heat the oven to 325 degrees.
- Spread the filling evenly over the cooled crust and smooth the top.
- Sprinkle with the reserved oat topping.
- Bake the bars until a toothpick inserted into the center comes out with a few moist crumbs attached and the filling begins to pull away from the sides of the pan, 25 to 30 minutes, rotating the pan halfway through baking.
- Let the bars cool completely in the pan, set on a wire rack, about 2 hours.
- Remove the bars from the pan using the foil, cut into squares, and serve.