• Preheat the oven to 350 degrees then line 2, 12 cup muffin tin with paper liners (you will get 16 cupcakes total) and set aside.
• To a medium-size mixing bowl add the gluten free flour blend, baking soda, baking powder, and salt then whisk to combine and set aside.
• To the bowl of an electric mixer, or to a large glass bowl if using a hand-held mixer, add the butter, vegetable oil, and sugar then beat on medium speed (6/10) until fluffy and pale, 1 minute. Scrape down the sides of the bowl then add 1 egg and mix on low speed until just combined. Add the second egg and vanilla then mix until just combined. Scrape down the sides of the bowl.
• Add half the dry ingredients to the bowl then mix to combine. Add half the buttermilk then mix to combine. Scrape down the sides of the bowl then add the remaining dry ingredients and the remaining buttermilk, mixing until just combined between each addition.
• Give the batter a few big stirs with a spatula to ensure all the ingredients are well combined then fill each lined muffin cup 2/3 of the way full with batter. Bake for 17-19 minutes, or until a toothpick inserted into the center of the cupcakes comes out clean, rotating the pan 180 degrees halfway through. The tops of the cupcakes should be deep golden brown - avoid underbaking to ensure your cupcakes turn out light and fluffy vs dense and gummy.
• Let the cupcakes cool in the tin for 10 minutes before removing to a cooling rack to cool completely. Once the cupcakes are completely cool, place them inside a storage container with a lid then let them sit for at least 8 hours – preferably overnight. This will ensure the cupcakes remain soft and stable like a regular cupcake, and won't crumble or fall apart.

For the Vanilla Buttercream Frosting:

• Add the softened butter to the bowl of an electric mixer, or to a large glass bowl if using a hand-held mixer, then beat on medium-high speed (8/10) until pale and creamy, 1 minute.
• Scrape down the sides of the bowl then add the powdered sugar, 2 Tablespoons milk, vanilla extract, and salt, if using. Mix on low speed until the powdered sugar is mostly wet then turn the speed up to medium (6/10) and beat for 2 minutes, scraping down the sides of the bowl halfway through. Add an additional Tablespoon milk if desired for a looser frosting then beat to combine.
• Add gel food coloring, if using, then beat to combine. Frost the cupcakes then top with sprinkles and serve.