Let the butter soften at room temperature or pop it into the microwave for a few seconds to soften (not melt!).
Preheat the oven to 300F. Prep a 9-inch baking pan by covering it in parchment paper.
Add the softened butter to a bowl and add the sugar. Beat together until thoroughly incorporated (a stand mixer makes this much easier).
Add the eggs one at a time, beating well after each. Add the vanilla and beat until incorporated.
Zest the lemon and add the zest to the butter mixture.
Using the previously made fruit paste, measure out 3 ½ cups and add it to the butter mix. Mix thoroughly to combine.
In a large mixing bowl, add the flour, baking powder, cloves, cinnamon, ginger, nutmeg, and salt. Whisk to mix.
Carefully add the dry ingredients to the wet ingredients. Mix thoroughly, but try to avoid over mixing if possible. The batter should be thick enough that your spoon can stand up in it.
Transfer the batter to your previously prepared baking dish and use a spatula to smooth over the top.
Bake for 40 minutes then check it to make sure it is fine. It will probably need another 20 or so minutes, but better safe than sorry. Expect it to be done after an hour. To test if the cake is done, insert a fork in the center. If it comes out dry, it should be done. If it comes out wet, keep cooking it. When the cake is done, remove it from the oven and allow to cool in the pan for 30 minutes.
When the cake is cool to the touch, remove from the pan and allow to continue cooking on a wire rack.
Let cool completely before cutting and serving.
Enjoy!