Forget Fudge—This Classic British Dessert Is the Best No Bake Holiday Treat

Name: Forget Fudge—This Classic British Dessert Is the Best No-Bake Holiday Treat
Ingredients: Nonstick cooking spray; 200g milk chocolate, coarsely chopped (7 ounces; about 1 1/3 cups); 100g dark chocolate, coarsely chopped (3 1/2 ounces; about 2/3 cup); 113g unsalted butter, softened (4 ounces; 8 tablespoons); 3 tablespoons (60g) golden syrup or light corn syrup; 10 digestive biscuits, crushed (5 1/4 ounces; 150g), see notes; 100g mini marshmallows (3 1/2 ounces; 2 cups); 50g glacé cherries, quartered (1 3/4 ounces; 1/3 cup); 25g (about 2 tablespoons) chopped white chocolate (optional)