Preheat the oven to 350. Add parchment paper rounds, or squares cut to size, to the bottom of two 8 or 9 inch round cake pans. Lightly grease with cooking spray.

Add the flour, sugar, baking soda, baking powder, salt and turmeric to a bowl and whisk to combine.Add the milk, oil, vinegar and vanilla, whisk to combine, there will be some lumps, that is ok.

Divide among prepared baking pans and bake for 35-40 minutes until top is golden yellow and a toothpick inserted in the center comes out clean.

While the cake is baking, prepare the frosting. Add the butter and shortening to a bowl and use a hand mixer to stand mixer to cream the butter and shortening together. Add the powdered sugar to the bowl 1 cup at a time and cream together on low speed. Add the vanilla and oat milk and cream together until smooth and creamy and a thick frosting has formed.

Remove cake from the oven and let cool completely. Invert the pans on a clean surface to let the cakes drop out. Frost one layer, top with the next layer of cake. Frost second layer and sides. Slice into 16 pieces.