Blackberry Fool

Name: Blackberry Fool
Yield: Makes 8 Servings
Ingredients: Pure vanilla extract, 1 teaspoon; Brandy, preferably blackberry, 1 tablespoon (optional); Powdered (icing) sugar, ¼ cup (1 oz/30 g); Heavy (double) cream, 2 cups (16 fl oz/500 ml), chilled; Blackberries, 2¼ cups (9 oz/280 g)