1. Preheat the oven to 350 degrees F. Line 24 muffin tins with paper liners.

Using an electric mixer, cream the butter and vanilla sugar together until fluffy, about 2 to 3 minutes. Add the eggs, one at a time, and vanilla extract, beating until smooth.

2. Combine the flour, baking soda, nutmeg, and salt in a medium bowl. Add half the flour mixture to the creamed butter, then add the sour cream, and then the rest of the flour. Beat until combined, taking care not to over mix. Gently fold in the chopped apples.

3. Divide batter between prepared muffin tins, filling each liner about half way with batter. Bake until a toothpick inserted into the center of the cupcakes comes out clean and the tops spring back when pressed gently, about 20 minutes. Cool the cupcakes in the tin on a rack, for 10 minutes then remove from the tin and cool completely.

4. Put apple butter into a small pastry bag with an open tip. Squeeze about a teaspoon into the center of each cupcake.

5. To make the frosting: Beat the cream cheese and butter together in a bowl with an electric mixer until fluffy, about 2 minutes. Add in vanilla and lemon juice. On low speed, gradually add in confectioners' sugar and beat until well combined. Top cupcakes with frosting. Serve.