Preheat your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan or line with parchment paper.

In a large bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.

Add the buttermilk, vegetable oil, eggs, and vanilla extract. Beat on medium speed until well combined.

Lower the mixer speed and carefully add the boiling water until just combined.

Pour the batter into the prepared cake pan and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.

In a medium saucepan, sprinkle gelatin over cold water and let it bloom for about 5 minutes.

Heat the mixture on low until the gelatin dissolves. Remove from heat and add the raspberry puree and powdered sugar. Let it cool slightly.

Whip the cream in a separate bowl until stiff peaks form. Gently fold the whipped cream into the raspberry mixture until well combined.

Once the chocolate cake is cool, slice it horizontally into two equal layers.

Place one layer on a serving plate and spread half of the raspberry mousse on top.

Add the second layer and spread the remaining mousse over the top and sides.

Refrigerate for at least 4 hours or overnight to allow the mousse to set.

Top with fresh raspberries, whipped cream, and shaved chocolate if desired. Slice, serve, and enjoy!