Make the chocolate cake:

1. Preheat oven to 350°F and grease a a 9-inch springform pan with baking spray.
2. In a large mixing bowl, whisk together flour, cocoa powder, baking powder, and salt, until combined. Set aside.
3. In another large bowl, add eggs, sugar, sour cream, vegetable oil, and vanilla. Whisk together until smooth and well combined.
4. Add the dry ingredients into the wet, and whisk until half-combined. Then, pour in the hot coffee, then whisk until everything is smooth and well-combined.
5. Pour the cake batter into the prepared pan, and bake for 44-55 minutes, until an inserted toothpick comes out clean. Allow to cool in the pan until cooled completely to room temperature.
6. When cooled, remove the cake from the pan and cut off any doming from the cake to make a flat surface. Place back into the springform pan.

Make the chocolate mousse:

1. While the cake is baking, place the chocolate and heavy cream into a microwave-safe bowl. Place into the microwave and heat in 30 second intervals, stirring in between, until the chocolate has fully melted and is smooth.
2. Place into the fridge to cool for 30 minutes (cooled but not firm).
3. Remove from fridge, and add confectioners’ sugar and vanilla. Using an electric hand mixer or stand mixer, beat the mixture until soft peaks have formed.
4. Whisk together the gelatin and boiling water until smooth. Drizzle it into the mousse while the mixer is running. Continue beating until stiff peaks have formed.
5. Spread the chocolate mousse evenly over chocolate cake layer inside the spring form pan.
6. Cover lightly with plastic wrap, then place into the fridge to fully set (at least 4 hours, or preferably overnight).

Make the chocolate ganache glaze:

1. Place chocolate and heavy cream into a microwave safe bowl. Place into the microwave, then heat in 30 second intervals, stirring in between, until the chocolate has fully melted and is smooth.
2. Pour and spread over the cooled and set mousse layer.
3. Refrigerate again until ganache is fully set.
4. Carefully remove the chocolate mousse cake from the springform pan. For clean slices, run a sharp knife under hot water and wipe dry between cuts. Slice and serve chilled with fresh berries, whipped cream, or an extra drizzle of chocolate ganache if desired.