Preheat the oven to 350 °F. Spray three 9-inch cake pans with nonstick spray with flour.

In a large bowl, combine the flour, 1 3/4 cups sugar, baking soda, baking powder and salt.

In a medium bowl, combine the water and espresso powder, stirring until the espresso dissolves. Add the oil and eggs, whisking until smooth. Add the espresso mixture to the flour mixture, beating at medium speed with a mixer until combined. Stir in the sour cream. Spoon the batter evenly into the prepared pans.

Bake until a wooden pick inserted in the center comes out clean, 18 to 22 minutes. Cool in the pans on wire racks for 10 minutes. Remove from the pans, and cool completely on wire racks. Brush each cake layer with 1 tablespoon coffee-flavored liqueur.

In a small saucepan, combine the chopped chocolate and 1 3/4 cups heavy cream. Cook over medium-low heat, stirring constantly, until chocolate is melted and smooth. Cool for 15 minutes.