(above) I added some extra oats and chocolate chunks to sprinkle on top of the blondie before baking.
1/2 cup (1 stick) unsalted butter, room temperature, plus more for pan
1/2 cup packed light-brown sugar
1 large egg
1 cup all purpose flour
1 cup old-fashioned rolled oats
- Preheat oven to 350 degrees. Brush an 8-inch square baking pan with butter. Line bottom and two sides with a strip of parchment paper, leaving a 2-inch overhang on both sides. Butter paper, and set pan aside.
- Using an electric mixer, beat butter and sugar until light and fluffy. Add egg and vanilla, and beat until combined. In a separate bowl, whisk together flour, white sugar, baking powder and salt. With mixer on low, gradually add in flour mixture; mix just until combined. Mix in 3/4 cup oats. Mix in chocolate chunks. Pour batter into prepared pan.
- Using an offset metal spatula or table knife, smooth batter evenly. Sprinkle with remaining oats and extra chocolate chunks, pressing gently to adhere. Bake until a toothpick inserted in center comes out with only a few moist crumbs attached, 30 to 35 minutes. Let cool in pan 30 minutes.
- Using overhang, transfer blondie (still on paper) to a wire rack to cool completely. Place on a cutting board (peel off paper); using a serrated knife, cut into 16 squares.