Start by crushing chocolate sandwich cookies into fine crumbs using a food processor. Melt unsalted butter and mix it with the cookie crumbs until well combined. Firmly press the mixture into the bottom of silicone molds to form the crust. Place the molds in the freezer for about 15 minutes to set.

In a saucepan, combine fresh or frozen blackberries with sugar and water over medium heat. Cook the mixture until the blackberries soften and break down, approximately 5-7 minutes. Once ready, blend the mixture until smooth, and strain it through a fine mesh sieve to remove the seeds, leaving you with a vibrant puree for your Mini Blackberry Mousse Cakes.

In a small bowl, sprinkle gelatin over fresh lemon juice and let it sit for about 5 minutes to bloom. After blooming, gently warm the mixture in the microwave or over a double boiler, stirring until fully dissolved. Remove from heat and allow it to cool slightly before incorporating it into the cooled blackberry puree.

In a separate bowl, whip heavy cream until soft peaks form. Carefully fold the whipped cream into the cooled blackberry puree, using a gentle motion to maintain the airy texture of the mousse. This mixture will create the light and fluffy filling for your Mini Blackberry Mousse Cakes.

Once the crust has set, pour the blackberry mousse mixture into the prepared crusts, filling them about three-quarters full. Smooth the tops with a spatula and then refrigerate the assembled mousse cakes for at least 4 hours, or until they are completely set and firm to the touch.

To make the glaze, heat the heavy cream in a small saucepan over low heat until it just begins to simmer. Pour the hot cream over white chocolate chips in a mixing bowl, letting it sit for a couple of minutes. Stir the mixture until it is smooth, then cool it slightly before pouring over the set mousse for a glossy finish.

Once the glaze is ready and has slightly cooled, gently pour it over the chilled mousse cakes, ensuring an even coating. Return the cakes to the refrigerator for another 30 minutes to allow the glaze to firm up. Finally, garnish with fresh blackberries and edible violets or pansies for a stunning presentation before serving your delightful Mini Blackberry Mousse Cakes.