Line a muffin tin with paper cupcake liners and set aside.
Preheat oven to 350 degrees F.
In a large bowl, beat together sugar and eggs until creamy.
Add butter into sugar and egg mixture and beat some more. Add vanilla.
In a separate bowl, sift together all-purpose flour, nutmeg, cinnamon, baking soda and salt.
Add dry ingredients into wet ingredients one third at a time. Mix thoroughly.
Add sour cream and mix.
Add apple cubes and fold into batter.
Scoop about ¼ cup of batter into each muffin section.
Bake for 15-18 minutes. Allow to cool before decorating.