For the Cupcakes:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.
2. Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
3. Cream Butter and Sugar: In a large bowl, beat the softened butter and granulated sugar together until light and fluffy (about 3-4 minutes).
4. Add the Eggs and Flavorings: Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and orange zest.
5. Alternate Wet and Dry Ingredients: Add the dry ingredients to the wet ingredients in three additions, alternating with the milk and orange juice. Begin and end with the dry ingredients, mixing just until combined.
6. Fill the Cupcake Liners: Divide the batter evenly among the 12 cupcake liners, filling each about 2/3 full.
7. Bake: Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let the cupcakes cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely.

For the Orange Buttercream Frosting:

1. Make the Frosting: In a large bowl, beat the softened butter with an electric mixer until smooth and creamy (about 2 minutes). Gradually add the powdered sugar, about 1/2 cup at a time, and beat until fully combined.
2. Add Orange Flavoring: Mix in the orange juice, orange zest, vanilla extract, and a pinch of salt. Continue to beat until the frosting is light and fluffy, adjusting the consistency by adding more powdered sugar or orange juice if needed.
3. Frost the Cupcakes: Once the cupcakes have completely cooled, use a piping bag or spatula to frost the cupcakes with the orange buttercream.