Lemon Blueberry Mousse Cake

Name: Lemon Blueberry Mousse Cake
Cuisine: European, Mediterranean, French
Ingredients: 60 g unsalted butter, softened; 60 ml vegetable oil; 125 g granulated sugar; 2 teaspoons vanilla extract; 2 large eggs; 125 g self raising flour; 30 ml whole milk; 100 g granulated sugar; 100 ml lemon juice; 8 g gelatin powder; 2 tablespoons cold water; 500 g fresh blueberries; 150 g granulated sugar; 500 ml double cream; Plus some purple food colouring (optional); 5 g gelatin powder; 1 tablespoon cold water; 250 g fresh blueberries; 50 ml water