Combine the flour and baking soda in a mixing bowl. Set aside.

In another bowl, mix together the oil, peanut butter, and banana until creamy.

Mix in the egg.

Add the flour mixture until well combined. Slowly pour and mix in the milk.

Pour into an 6-inch or 8-inch round pan or muffin pan. Bake 25-30 minutes or until cooked through. Let cool for 10 minutes.

For the frosting, mix the ingredients yogurt and peanut butter together until well combine and fluffy.

Once the cake is cooled, cover with frosting.