Berry Compote Crunch with Ginger Molasses Mousse

Name: Berry Compote Crunch with Ginger Molasses Mousse
Ingredients: 2 pints blackberries, plus more for garnish; 2 pints blueberries, plus more for garnish; 2 pints raspberries, plus more for garnish; 1 lemon, zested and juiced; 1 cup brown sugar; 1 stick (8 tablespoons) unsalted butter; 2 teaspoons ground cinnamon; 3 teaspoons cornstarch; 1/4 cup water; 3 cups hazelnuts; 3 cups oatmeal; 2 teaspoons vanilla bean paste; 1 teaspoon ground cinnamon; 1 teaspoon salt; 2 sticks (1 cup) unsalted butter, melted; 2 cups mascarpone; 1 cup cream cheese; 1 cup heavy whipping cream; 1 cup confectioners' sugar; 3 teaspoons ground ginger; 2 teaspoons grated fresh ginger; 1/2 cup molasses; 1 whole lemon, zested, plus zest for garnish