Preheat the Oven: Start by preheating your oven to 350°F (175°C) and prepare a cupcake tray lined with paper liners.
Mix the Base: In a large mixing bowl, beat together the softened butter, brunette sugar, and granulated sugar until the mixture is light and fluffy. Gradually add in the eggs, one at a time, followed by the vanilla extract.
Combine Dry Ingredients: In another bowl, sift together the flour, baking powder, sodium bicarbonate, and salt. Gradually mix the dry ingredients into the wet ingredients, alternating with the milk, until everything is well combined.
Add the Nuts: Fold in the chopped nuts gently until evenly distributed.
Create the Surprise: Fill each cupcake liner with about one-third of the batter. Then, drop a teaspoon of caramel in the center of each cupcake and cover with more batter until reaching two-thirds full.
Bake to Perfection: Place the cupcake tray in the preheated oven and bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean. Let the cupcakes cool in the tray for a few minutes before transferring them to a wire rack.
Decore and Enjoy: Finally, drizzle additional caramel on top and sprinkle chopped nuts for a delightful finishing touch!