Preheat the oven to 325° F. Line an 8-inch square cake pan with a double
thickness of waxed paper.
In a medium saucepan over medium heat, combine the butter, sugar, Guinness,
raisins, sultanas, and mixed peel. Bring gently to a boil and cook, stirring
frequently, for 3 to 4 minutes, or until slightly thickened. Remove from the
heat and let cool for 10 to 15 minutes.
In a medium bowl, sift together the flour and Mixed Spice. Stir in the cooked
fruit and cherries. Add the eggs and stir until well-blended. Spoon into the
prepared pan and smooth the top. Bake on the middle shelf of the oven for 60
to 70 minutes, or until a skewer inserted into the center comes out clean. Remove
from the oven and let cool on a wire rack for 30 minutes. Invert the cake onto
the rack to cool completely. Remove the lining paper. If not serving immediately,
wrap the cake in plastic wrap, then aluminum foil, and store in a cool, dark
place for several weeks to allow the cake to mature.