Preheat and prepare
Preheat your oven to 350°F (175°C). Line a muffin tin with cupcake liners.
Mix dry ingredients
In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
Cream butter and sugar
In a large bowl, beat the butter and sugar until light and fluffy. Add eggs one at a time, mixing well after each. Stir in vanilla extract.
Combine wet and dry ingredients
Gradually add the dry ingredients to the wet mixture, alternating with buttermilk. Begin and end with the dry ingredients. Fold in the sprinkles gently to avoid color bleeding.
Bake the cupcakes
Divide the batter evenly among the cupcake liners, filling each about 2/3 full. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let the cupcakes cool completely on a wire rack.
Prepare the frosting
Beat the butter until creamy. Gradually add powdered sugar, heavy cream, and vanilla extract. Divide the frosting into two bowls and color one bowl yellow and the other orange, if desired.
Decorate the cupcakes
Use a piping bag to swirl the yellow and orange frostings together for a candy corn effect. Garnish each cupcake with a piece of candy corn.