Preheat oven to 350 degrees and muffin tins with 15 cupcake liners or spray well with non-stick spray.

In a large bowl, whisk together the gluten free flour, xanthan gum, baking powder, salt, and sugar. Set aside.

In a medium bowl, whisk together the eggs, lemon zest, lemon juice, lemon extract, vanilla extract, milk, and avocado oil. Pour the wet ingredients into the dry ingredients and stir until combined.

Transfer the batter to the prepared muffin tins and fill each one 2/3 of the way with batter. Bake at 350 degrees for 17-19 minutes or until a toothpick comes out clean. (Mine take 18 minutes)

 Remove from the pans and cool completely on a wire rack before frosting.

Add the cream cheese and butter to a bowl of a stand mixer fitted with the paddle attachment. Beat together until smooth, about 1 minute.

Scrape down the sides of the bowl and add the powdered sugar and mix on the lowest speed until the sugar is incorporated. Add the vanilla and lemon juice and mix an additional 30 seconds to 1 minute until the frosting is smooth and creamy.

Frost the cooled cupcakes as desired and store in the refrigerator. Bring to room temperature before serving. Cupcakes are best if eaten within 2-3 days. These cupcakes also freeze well.