First, preheat your oven to 350°F (175°C). Line a cupcake pan with paper liners.

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

In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the eggs one at a time, followed by the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, mixing until just combined.

Stir in the plain Greek yogurt until the batter is smooth and well blended.

Fill each cupcake liner about two-thirds full with the cupcake batter.

Bake the cupcakes in the preheated oven for 18 to 20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.

Remove the cupcakes from the oven and let them cool in the pan for a few minutes before transferring them to a wire rack to cool completely.

Next, make the vanilla buttercream frosting. In a large mixing bowl, beat the softened butter until smooth and creamy.

Gradually add the powdered sugar, one cup at a time, and continue beating until the frosting is fluffy and well combined.

Mix in the vanilla extract.

Add the milk, one tablespoon at a time, until you reach your desired consistency. The frosting should be smooth and easy to spread.

Once the cupcakes are completely cooled, frost them with the vanilla buttercream frosting using a piping bag or a spatula.

Optionally, you can decorate the cupcakes with sprinkles, edible flowers, or any other toppings of your choice for a fun and festive touch. Finally, serve!