Preheat your oven to 350 degrees F, spray two 8 inch cake pans with non stick spray and line bottom with parchment paper. Set aside.
In a large mixing bowl, beat together your oil, butter, sugar, eggs, vanilla, milk, and sour cream with an electric mixer.
In a separate bowl, whisk together your gluten free flour, almond flour, the baking powder, and salt.
Mix your flour mix in to your wet ingredients, mix until smooth.
Fold in your sprinkles.
Evenly pour your batter in to each of your prepared cake pans. Bake for 40-45 minutes or until a toothpick inserted to the middle comes out almost clean.
Allow to cool in your cake pan for 20 minutes and then transfer to a wire cooling rack to cool completley.
Frosting:
Once your cakes have completely cooled, make your frosting by beating your butter until smooth.
Slowly beat in your powdered sugar, then the milk, and vanilla.