In a large bowl, combine the mixed dried fruit, dark rum, red wine, and stout beer. Cover the bowl and let the fruit soak overnight or for at least 24 hours.
Preheat your oven to 325°F (165°C). Grease and line a 9-inch (23 cm) round cake pan with parchment paper.
In a separate large mixing bowl, cream together the softened butter and brown sugar until light and fluffy.
Beat in the eggs, one at a time, ensuring each egg is fully incorporated before adding the next.
In a medium bowl, whisk together the all-purpose flour, baking powder, cinnamon, nutmeg, and allspice.
Gradually add the dry ingredient mixture to the butter mixture, alternating with small amounts of the soaked fruit mixture. Begin and end with the dry ingredients.
Stir in the vanilla extract and browning sauce (if using), ensuring everything is well combined.
Pour the batter into the prepared cake pan, spreading it evenly.
Bake in the preheated oven for about 2 to 2.5 hours, or until a toothpick inserted into the center of the cake comes out clean.
Remove the cake from the oven and let it cool in the pan for about 10 minutes. Then transfer it to a wire rack to cool completely.