Roasted Almond, Citrus and Whisky Christmas Cake

1 cup good-quality fruit mince (see Cook’s note)75 grams whole roasted almonds, finely chopped½ cup dried cranberries, roughly chopped150 grams butter, very soft150 grams brown sugar2 teaspoons ground mixed spice1 teaspoon ground cinnamon1 teaspoon vanilla extract finely grated zest 1 large orange and 1 large lemon¹⁄3 cup orange juice2 large eggs, size 72 tablespoons whisky150 grams ground almonds (almond meal)50 grams brown rice flour1 tablespoon baking powder½ teaspoon sea salt¹⁄3 cup slivered almonds (optional)