Ingredients
13 tablespoons unsalted butter, softened, plus more for pan
2 1/2 cups all-purpose flour
1 1/2 teaspoons baking powder
3/4 teaspoon salt
1 1/2 cups packed light-brown sugar
3 large eggs
1 1/2 teaspoons pure vanilla extract
Preparation
Preheat oven to 350 degrees. Butter 9-by-13-inch cake pan; line with parchment paper, allowing 2-inch overhang. Butter parchment. Whisk flour, baking powder, and salt in a medium bowl. Put butter and brown sugar into mixer bowl; mix on medium-high until pale and fluffy. Mix in eggs and vanilla. Reduce speed to low. Add flour mixture; mix until just combined.
Spread batter into prepared dish; smooth top. Bake until a cake tester inserted into center comes out with only a few moist crumbs attached, 25 to 30 minutes. Let cool in dish 40 minutes. Lift out, and let cool completely on wire rack.
