Preheat oven to 350F. Butter the bottom and sides of a 8 inch metal baking pan. Put a long piece of parchment paper in the bottom of the pan, letting the parchment extend up two sides of the pan and overhang slightly on both ends. (This will make it easy to remove the bars from the pan after they have baked.) Butter the parchment.

In a small, heatproof bowl, melt butter and chocolate together. Stir until combined and very smooth. Set aside to cool for a few minutes.

In a large bowl, whisk together eggs, sugar and vanilla extract. Add chocolate mixture and stir until smooth. Add flour and baking soda and stir until just combined and no streaks of dry ingredients remain.

Spread into prepared baking pan. Bake at 350 for 25-30 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack.

For the filling, in a small bowl combine cream and coffee granules. Stir until the coffee is dissolved.

In the bowl of a stand mixer fitted with the paddle attachment,  cream butter and confectioners sugar until light and fluffy. Beat in coffee mixture.  Spread over brownies.

For the chocolate ganache, in a small saucepan over low heat combine chocolate and heavy cream. Cook and stir until chocolate is melted and mixture is thickened. Cool slightly. Carefully spread over filling. Let  chocolate gancahe set up completely before cutting.