Set your oven to 350°F (175°C) and prepare a cupcake pan by lining it with cupcake liners.
In a large mixing bowl, combine the flour, sugar, baking powder, and baking soda, then whisk until well blended.
Add the softened butter and mix on medium speed until the texture becomes crumbly.
In a separate bowl, whisk together the eggs, vanilla extract, buttermilk, and green food coloring. Slowly incorporate this wet mixture into the dry ingredients, stirring until smooth.
Evenly distribute the batter into the cupcake liners, filling each approximately two-thirds full.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool in the pan for about 5 minutes before moving them to a wire rack to cool fully.
In a large bowl, whip the softened butter until it becomes smooth and creamy
Slowly mix in the powdered sugar, beating on low until fully incorporated. Pour in the heavy cream and beat on medium speed until light and fluffy.
After the cupcakes have fully cooled, generously frost them with the green buttercream. For a decorative touch, use a piping bag to apply the frosting.
If desired, decorate the frosted cupcakes with shamrock sprinkles, edible glitter, or any other festive toppings.
