Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing them lightly with butter or cooking spray.

In a medium bowl, whisk together 1 ½ cups of all-purpose flour, ½ cup of unsweetened cocoa powder, 1 cup of granulated sugar, and 1 teaspoon of baking powder until well incorporated.

In a large mixing bowl, whisk together 2 eggs, ½ cup of vegetable oil, and 1 cup of milk until frothy and well combined. Gradually pour the wet ingredients into the bowl of dry ingredients and stir gently until just combined.

Divide the batter evenly between the prepared cake pans and place them in the preheated oven. Bake for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean.

In a small saucepan, melt 8 ounces of dark chocolate chips over low heat, stirring continuously until smooth. In a separate bowl, heat 1 cup of fresh raspberries until they begin to release their juices, then mix in 1 tablespoon of agar-agar powder until fully dissolved.

Once the chocolate cakes are completely cool, place one layer on a serving plate. Spread half of the raspberry chocolate mousse evenly over the top, then gently place the second layer on top. Spread the remaining mousse over the top and sides of the cake.

Cover the assembled cake with plastic wrap and refrigerate for at least 2 to 4 hours.

Once chilled, take out your stunning Heavenly Raspberry Chocolate Mousse Cake, slice into delightful portions, and serve immediately.