Preheat your oven to 350°F (175°C) and line a cupcake tin with paper liners.

In a large mixing bowl, cream together softened unsalted butter and granulated sugar until light and fluffy, then add in eggs and vanilla extract, mixing until smooth.

In a separate bowl, whisk together all-purpose flour, baking powder, baking soda, salt, and ground nutmeg.

Gradually combine the dry ingredients with the wet mixture, alternating with buttermilk until just combined.

In a small bowl, mix together brown sugar, ground cinnamon, and optional chopped nuts.

Spoon about one tablespoon of batter into each liner, sprinkle with cinnamon filling, then top with another tablespoon of batter.

Bake for 18-20 minutes or until a toothpick comes out clean. Cool in the pan for 5 minutes before transferring to a wire rack.

Allow the cupcakes to cool completely before frosting.

For the frosting, beat together cream cheese and unsalted butter, then gradually add sifted powdered sugar and vanilla extract, adjusting consistency with milk as needed.

Frost each cupcake and drizzle with caramel sauce if desired.