This cheerful Birthday Sheet Cake is the perfect finale for any birthday party. As this is not a layer cake, the vegan buttercream frosting doesn't need to be thick enough to hold a second cake layer. It's silky, smooth and dairy-free.
Sift and whisk together the flour, sugar, xanthan gum baking soda, baking powder and salt.In a separate bowl place the plant milk, vanilla and vinegar whisking to blend completely. Pour the wet mixture into the dry and mix until batter is smooth. Pour the mixture into a baking sheet and bake 365F 25-30 minutes until the top of the cake is ready and set.When cool, transfer to refrigerator to chill before frosting.