1️⃣ Prepare the Chocolate Cake Layers:

1. Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. 🧑‍🍳
2. In a large mixing bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk to combine. 🍫
3. Add the eggs, milk, oil, and vanilla extract to the dry ingredients. Mix on medium speed until the batter is smooth and well combined.
4. Carefully pour in the boiling water and mix on low speed until the batter is thin and fully combined. Be careful, as the batter will be quite liquid. 💦
5. Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
6. Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

2️⃣ Make the Lavender Blueberry Filling:

1. In a medium saucepan, combine the blueberries, lavender, sugar, cornstarch, and lemon juice. Cook over medium heat, stirring frequently, until the blueberries release their juices and the mixture thickens, about 10 minutes. 🍇
2. Remove from heat and strain the mixture through a fine mesh sieve to remove the lavender and any blueberry skins. Set aside to cool completely. 🌸
3. Once cooled, whip the heavy cream until soft peaks form. In a separate bowl, beat the mascarpone cheese until smooth. Gently fold the whipped cream into the mascarpone, then fold in the blueberry mixture until well combined.

3️⃣ Prepare the Blueberry Glaze:

1. In a small saucepan, combine the blueberries, sugar, water, and lemon juice. Cook over medium heat, stirring occasionally, until the blueberries burst and the mixture thickens slightly, about 5-7 minutes. 🍯
2. Remove from heat and strain the mixture through a fine mesh sieve to remove the solids, leaving a smooth glaze. Allow it to cool to room temperature.

4️⃣ Assemble the Cake:

1. Place one of the chocolate cake layers on a serving plate or cake stand. Spread half of the lavender blueberry filling over the top, spreading it evenly to the edges. 🍰
2. Place the second cake layer on top and spread the remaining filling over the top layer.
3. Pour the cooled blueberry glaze over the top of the cake, allowing it to drip down the sides for a dramatic effect.

5️⃣ Decorate and Serve:

1. Arrange fresh blueberries and blackberries on top of the cake. Garnish with fresh lavender sprigs if desired for an extra touch of elegance. 🌿
2. Refrigerate the cake for at least 1 hour before serving to allow the flavors to meld together. Serve chilled and enjoy this dreamy creation! ❄️