1. Place the chocolate in a heat proof bowl. Add the extract.
2. Heat the cream until just simmering. Pour over the chocolate and let it sit for 5 minutes.
3. Stir until smooth and set aside.

1. Preheat the oven to 350 degrees. Line two muffin tin with paper liners. Set aside.
2. Whisk flour, cocoa powder, salt, and baking soda in a medium sized bowl. Set aside.
3. Add the butter and sugar to the bowl of an electric mixer. Beat with the paddle attachment at medium speed until incorporated.
4. Stir in the melted 2 oz chocolate. Mix until it is smooth. Add the eggs and egg yolks followed by the oil and vanilla.
5. Fold in the dry ingredients followed by the sour cream and water.
6. Divide the dough into your prepared liners, filling 3/4 full. Bake 18 minutes, or until a toothpick comes out clean.
7. Cool completely.

1. Add the butter to the bowl of an electric mixer. Beat on medium speed with the paddle attachment for 2 minutes.
2. Scrape the sides of the bowl. Add the cocoa powder and powdered sugar, one cup at a time, and stir until combined.
3. Stir in the salt, extracts, and creams until just combined. Scrape the sides of the bowl.
4. Turn the speed of the mixer to low/medium. Allow the frosting to be stirred for 5 to 7 minutes, or until light and fluffy.

Assembly:
1. Remove the center of the cooled cupcakes.
2. Add a heaping spoonful of the chocolate mint filling to each.
3. Top with the chocolate buttercream.