Shortbread Caramel Brownie Bars

Ingredients

• 0.5 teaspoon double-acting baking powder 
• 0.8 lb butter 
• 12 ounces individually wrapped caramels such as kraft soft
• 2 tablespoons cornstarch 
• 3 large eggs 
• 2.5 cups flour all-purpose
• 0.3 teaspoon salt 
• 10 ounce bittersweet chocolate finely chopped
• 1.3 cups sugar 
• 1 tablespoon vanilla 
• 0.3 cup milk whole

Equipment

• food processor
• bowl
• frying pan
• oven
• knife
• whisk
• blender
• baking pan
• microwave
• spatula
• skewers

Directions

1. Cut 1 cup butter into chunks. In the bowl of a food processor, combine 2 cups flour, 1/2 cup sugar, cornstarch, and the butter chunks. Whirl until dough comes together. Press evenly over the bottom of a buttered 9- by 13-inch baking pan.
2. Bake in a 325 regular or convection oven until top feels dry and is just beginning to brown, about 25 minutes.
3. Let cool completely.
4. Meanwhile, unwrap caramels and place in a microwave-safe bowl with milk. Cook in a microwave oven on full power (100%) for 1 minute. Stir mixture, then cook and stir at 30-second intervals until melted and smooth, about 3 minutes longer.
5. Spread caramel mixture evenly over cooled crust and chill until firm, about 20 minutes.
6. In a large bowl set over a pan of barely simmering water (bottom of bowl should not touch water), stir chocolate and remaining 1/2 cup butter often until melted and smooth.
7. Remove bowl from over water and, with a whisk or a mixer on medium speed, beat in remaining 3/4 cup sugar, eggs, and vanilla until well blended. Stir in remaining 1/2 cup flour, baking powder, and salt until well blended.
8. Pour chocolate mixture over caramel layer and use a knife or spatula to spread level, completely covering caramel.
9. Bake in a 350 regular or convection oven until a wooden skewer inserted into the chocolate layer comes out clean, 35 to 40 minutes.
10. Let cool completely, then cut into 24 bars.