Preheat the oven to 350°F (175°C) and line a muffin tin with paper cupcake liners.
Cream the softened butter and granulated sugar together in a mixing bowl using an electric mixer or whisk until the mixture is light, fluffy, and pale in color, about 3-4 minutes. Watch for a volume increase and a smooth texture.
Add eggs one at a time, beating well after each addition. The batter should become more elastic and slightly thicker, with a glossy appearance. Incorporate vanilla extract and vanilla bean paste, mixing until evenly distributed.
In a separate bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture in three additions, mixing on low speed or folding gently after each addition. The batter should become smooth and thick, with no lumps remaining.
Spoon the batter into the prepared cupcake liners, filling each about two-thirds full. Tap the pan lightly on the counter to remove air bubbles and ensure even rising.
Bake in the preheated oven for 20 minutes, or until the cupcakes are golden brown on top and a toothpick inserted into the center comes out clean. The edges should be slightly domed and firm to the touch.