Step 1 Heat the oven to 350 degrees.
Step 2 Beat the butter and sugar in a bowl on medium speed until creamy, 3 to 4 minutes. Mix the flour and baking powder together and beat into the butter mixture.
Step 3Pat the dough into the bottom of a 13x9-inch baking pan. Bake until golden brown, 20 to 25 minutes. Remove from the oven. Let stand until cool.