Parchment Paper
1 oz. chopped semisweet chocolate
1/2 oz. chopped milk chocolate
12 T melted + 3 T room temperature unsalted butter
1/2 cup sour cream
2 large eggs, beaten
1 1/2 tsp apple cider vinegar
1/2 tsp + 1/2 tsp vanilla extract
1 T red food coloring
2 1/4 cups all-purpose flour
1 cup granulated sugar
1/4 cup unsweetened cocoa power
2 tsp baking powder
1/4 tsp baking soda
1/2 tsp salt
8 oz. room temperature cream cheese
2 1/2 cups sifted confectioner's sugar

Preheat oven to 375 degrees.  Line 2 large baking sheets with parchment paper (the best thing ever!).

Combine semisweet chocolate and  chopped milk chocolate in a microwaveable bowl.  Microwave at 50% power until melted, about 2 minutes.  Whisk until smooth.

In a large bowl, combine melted unsalted butter, sour cream, eggs, apple cider vinegar, vanilla extract, and red food coloring in a separate bowl and set aside.

In a separate bowl, combine flour, granulated sugar, cocoa powder, baking power, baking soda, and salt.

Add the flour mixture to the butter mixture in 4 equal batches, whisking each batch completely before adding the next.  Stir in the melted chocolate.

Scoop heaping tablespoons of batter onto baking sheets and smooth the tops with a damp finger.  Bake until the cookies spring back when lightly pressed, 8-10 minutes.  Let cool 10 minutes then transfer to cooling racks to cool completely while making the filling.

For the filling, beat room temperature cream cheese and 3 T room temperature unsalted butter.  Add sifted confectioner's sugar and 1/2 tsp vanilla extract until combined.

Scoop a heaping tablespoon of filling onto 1/2 of the cooled cookies.  Top each with the remaining cookies to create "sandwiches."  Refrigerate at least 30 minutes before serving.