1. Preheat the oven to 350 degrees.
2. Grease two 9-inch cake pans and line with parchment paper rounds for best results.
3. Combine all of the cake ingredients in a large blender.
4. Blend until mostly smooth. Batter will be thick and may require scraping down the sides of the blender with a spatula for complete mixing.
5. Divide the batter between the two cake pans and spread smooth.
6. Bake for 40 minutes, or until a toothpick inserted in the center comes out mostly clean.
7. Remove from the oven and cool for 30 minutes.
8. Carefully turn cakes out onto a wire rack and cool an additional hour before frosting.

1. Combine the heavy whipping cream, erythritol, vanilla, food coloring (if using) and gelatin in a large mixing bowl.
2. Beat well with a whisk or mixer, until stiff peaks form.
3. Carefully fold in the softened mascarpone cheese, strawberry puree, and chopped strawberries until well blended.

To assemble:

1. Place a cake layer upside down on a serving platter or cake plate.
2. Spoon 1/2 the strawberry mousse onto the top and spread to the edges.
3. Top with the 2nd cake layer and press down slightly.
4. Spoon the remaining strawberry mousse onto the top and spread to the edges.
5. Garnish with fresh strawberries if desired.
6. Store leftovers in a covered container in the refrigerator for up to 5 days, or in the freezer for up to 3 months.