Preheat the oven to 350F. Grease two 8-inch round pans or one 9×13 pan. I also like to line the bottom of the 8-inch round pans with a circle of parchment paper then grease again.

In a medium bowl, whisk together the gluten-free flour, baking powder and salt.

In the bowl of a stand mixer, add the eggs and sugar. Whip on medium-high speed for 3 minutes, until light and fluffy. With the mixer running on low, slowly drizzle in the oil. (You want to do this slowly so you don't lose the air that you've mixed in.) Mix in the lemon juice, lemon zest, vanilla extract and lemon extract.

With the mixer on low, add ⅓ of the dry ingredients. Mix until incorporated. Add the sour cream and mix to combine. Add another ⅓ of the dry ingredients and continue to mix. Add ½ of the milk followed by the last ⅓ of the dry ingredients. Add the remaining milk and stir until totally combined. (You want to add the dry ingredients alternately with liquid ingredients so the flour absorbs into the batter.)

Pour the batter into the prepared pans. Bake for 35-40 minutes until golden and a toothpick inserted into the center of each cake comes out clean.

If using 8-inch round pans, let the cakes cool in the pans for 15 minutes. Then turn out the cakes onto a wire rack to continue cooling. Cool completely before frosting.

In a large bowl using a hand-held mixer or stand mixer fitted with a whisk or paddle attachment, beat the butter on medium speed until creamy, about 2 minutes. Add the cream cheese and beat until completely smooth and combined.

Add powdered sugar, lemon juice, vanilla extract and pinch of salt with the mixer running on low. Increase to high speed and beat for 3 minutes. Add more powdered sugar if the frosting is too thin, and more lemon juice if the frosting is too thick.

Place 1 cake layer on your cake stand or serving plate. Evenly cover the top with frosting. Top with the 2nd layer and spread the remaining frosting all over the top and sides. Slice, serve, enjoy!