Butter two 9 inch cake pans and line the bottom of both with parchment paper. (I just trace the bottom of the pan on the paper and cut).
In a large bowl, whisk the flours, sugar, baking soda, xanthan gum, salt.
In a medium bowl, blend the milk, strawberry puree, oil, vanilla, and vinegar with hand beaters. Do NOT leave out the vinegar – I know it is a weird ingredient but it reacts with the baking soda to help with the rise!
Pour the wet ingredients into dry ingredients and combine. I started with hand beaters and finished with a spatula.
Pour into buttered cake pans. The batter is thick and kinda sticky just FYI.
Bake at 350 degrees for 35 minutes, or until a toothpick comes out clean. Check the cakes at the 25 minute mark though in case our ovens run differently.
Remove from oven and let cool for about 10 minutes. Then take the cakes out to cool completely on a wire rack.
Once the cakes are completely cooled you can make your frosting. Just put all the ingredients into a medium mixing bowl and beat with hand beaters until smooth.