Easy Vanilla Sheet Cake (in a 9"x13" pan!)

Name: Easy Vanilla Sheet Cake (in a 9"x13" pan!)
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 1 cup (2 sticks) unsalted butter, softened (see tips); 1 1/2 cups sugar; 1 1/2 teaspoons vanilla extract; 2 1/4 cups all-purpose flour; 2 1/4 teaspoons baking powder; 3/4 teaspoon salt; 1/2 cup buttermilk; 4 large eggs; 1 batch Raspberry Cream Cheese Frosting (or your preferred frosting); 1/4 cup sprinkles (optional, but highly recommended for extra cheer)