For Gluten-Free Lemon Cupcakes:

1. Preheat & Prep. To start, preheat oven temperature to 350 degrees F. Line a metal muffin pan with parchment paper liners.
2. Combine Lemon Juice & Milk. In a liquid measuring cup (or a small bowl), combine lemon juice and milk. Let sit for about 5 minutes.
3. Rub Zest Into Sugar. While the lemon juice and milk is sitting, rub lemon zest into the sugar in a large bowl. (This gets the lemon oil into the sugar and distributes the flavor.)
4. Combine Wet Ingredients. Add milk mixture, avocado oil, eggs, vanilla, and lemon extract to the sugar mixture. Whisk until well combined.
5. Combine Dry Ingredients. In a medium bowl, stir together flour blend, baking powder, baking soda, and salt. Stir the dry ingredients into the wet ingredients and mix until just combined.
6. Bake Cupcakes. Scoop the batter into your muffin cups, filling almost to the top. Bake cupcakes 17-20 minutes at 350 degrees or until a toothpick inserted in the center comes out clean, with just a few moist crumbs.
7. Brush Cupcakes With Lemon Syrup. Brush the warm cupcakes with your lemon syrup (see below) and cool completely before frosting.

For the Lemon Simple Syrup:

1. While the cupcakes are baking, make your lemon simple syrup. In a small bowl, combine sugar and lemon juice. Warm in the microwave 20-30 seconds and stir until the sugar is completely dissolved. (You can do this in a saucepan on the stove, if you prefer)
2. Brush Over Cupcakes. When the cupcakes come out of the oven and are still warm, brush the syrup over the cupcakes.
3. Cool Cupcakes. Transfer cupcakes to a wire cooling rack and cool cupcakes completely before frosting.

For the Lemon Frosting:

1. Beat Butter. When the cupcakes are completely cool, make your lemon frosting. In a large bowl (or the bowl of a stand mixer), beat the softened butter 1-2 minutes, or until light and fluffy.
2. Combine. Add lemon zest, vanilla, salt, 1 Tbsp. lemon juice, and 1 Tbsp. milk and beat to combine. Add 1 1/2 cups of the powdered sugar and beat to mix in. Add another 1 1/2 cups powdered sugar, 1 Tbsp. lemon juice, and 1 Tbsp. milk and beat until light, fluffy, and well incorporated.
3. Adjust For Consistency. If your frosting still seems a bit wet or seems slightly separated, add more powdered sugar 1 Tbsp. at a time until it reaches a better consistency. If your frosting seems a bit dry, you can add more milk or lemon juice 1 tsp. at a time until it’s thinned out to a better consistency.
4. Decorate Cupcakes. Transfer frosting to a piping bag (you may need to this with 1/2 the frosting at a time), and pipe onto your cooled cupcakes or spread the frosting on with an offset spatula. Add any desired decorations while the frosting is still soft and enjoy!
5. Note: you’ll have a generous amount of frosting here (about 2 1/2 cups), which may be more than you need depending on what style decoration you use.