Peanut Butter Sheet Cake with Chocolate-Cream Cheese Frosting

INGREDIENTS

Eggs, large

2/3 cup

Peanut butter, creamy

2 cups

All-purpose flour, unbleached

1 tsp

Baking powder

3/4 tsp

Baking soda

3/4 cup

Brown sugar, light packed

1/2 cup

Cocoa powder, unsweetened

1/2 cup

Granulated sugar

1/2 tsp

Kosher salt

3 cups

Powdered sugar

1/4 cup

Vegetable or other neutral-flavored oil

3/4 cup

Butter, unsalted

1 cup

Buttermilk

1 cup

Cream cheese

1/4 cup

(57 grams; 1/2 stick) butter, at room temperature

1 handful sprinkles (optional)