Toffee Bars

Check 3/4 cup (1 1/2 sticks) unsalted butter, plus more for the pan

Check 1 1/2 cups all-purpose flour, spooned and leveled

Check 1/2 teaspoon baking powder

Check 1 teaspoon fine salt

Check 3/4 cup packed light brown sugar

Check 1 large egg

Check 1/2 teaspoon pure vanilla extract

Check 6 ounces chocolate covered toffee bar, broken into small pieces (1 1/4 cups)