Preheat the oven to 300°F (150°C) and butter and line with parchment the bottom and sides of an 8×3 inch (20×7 ½ cm) cake pan. Set aside.
In a medium bowl, whisk together the flour, mixed spice, cinnamon, cloves and allspice. Set aside.
In a large saucepan, combine the raisins, sultanas, cherries, prunes, water, almond liqueur and lemon zest, and bring to a simmer over medium heat.
Cook the fruit for about 5 minutes, stirring frequently, until the liquid is absorbed.
Add in the butter and sugar and cook a few minutes longer until the butter has melted and the sugar has dissolved. Let cool for 10 minutes.
Fold in the flour and spice mix, almonds and eggs.
Pour into the prepared pan, level the top and bake for about 2 hours, until the cake is firm when pressed and a thin knife inserted in the center comes out clean.
Let cool completely in the pan before removing.
Store wrapped well at room temperature for up to 1 week or in the fridge for 2 weeks. Or see notes for how to age this cake and for longer storage.