In a small saucepan, stir together the raisins, lemon zest and O’Driscolls Irish Whiskey. Cover and warm over medium heat until the mixture is hot, about 2 minutes. Once steaming, remove from the heat and set aside to soak (cover tightly) for a minimum 1 hour (or up to overnight).
Preheat the oven to 350°F (180°C) and butter and line an 8x8-inch (20x20cm) cake pan with parchment paper and set aside.
In the bowl of a stand mixer fitted with a paddle attachment (or with a large bowl and a handheld electric mixer), beat together the butter and brown sugar on medium-high for 5 minutes, until pale and fluffy.
Add in the eggs one at a time and continue beating for another 3 minutes, scraping down the sides of the bowl a few times, to fully combine and aerate the eggs.
In a small bowl, combine the flour, baking powder, salt and cloves, then lower the speed of the mixer to low and gradually stir into the butter mixture until mostly combined.
Finally, pour in the raisin mixture and any remaining liquid in the bowl and stir on low until everything is evenly combined. (The batter will be very thick.)
Spread evenly into the prepared pan and bake for 45-55 minutes, until a toothpick cake tester inserted into the center comes out clean.
Let cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
Slice and spread on some butter and serve with a cup of tea. Store in an airtight container at room temperature for up to 5 days. For longer storage, freeze for up to 2 months.