The cupcake recipe can be found here and these cupcakes are delicious by themselves or with the frosting!
The frosting, which was adapted from this, I mixed:
2 sticks of butter
1/2-3/4 cup of the homemade dulce de leche (I didn't measure, I just scooped it in)
1 tsp. vanilla
3 TBSP Half & Half
1/4 tsp. cinnamon
Powdered Sugar to reach desired consistency
The end result was absolutely delicious ~ I brought them to work and was told they were the best cupcakes people had ever eaten. :)