The secret ingredient in this unusual ice cream? Beer! When pastry chef Michelle Antonishek of Gramercy Tavern prepared this dish for our Brewmaster's Banquet, she used Brooklyn Chocolate Stout, but at the restaurant she changes the beer with the seasons. The surprisingly subtle flavor of the ice cream cuts the rich sweetness of the heavily spiced cake.

Make the ice cream
1. To prepare the ice cream, combine the beer and simple syrup (made from equal parts sugar and water) in a medium saucepan. Simmer on low heat until the mixture has reduced by half. Remove the mixture from the pan and set aside to cool.

2. Combine the milk, cream, and 1/4 cup of the sugar in a medium saucepan and bring to a boil. In a separate bowl, whisk the yolks with the remaining 1/4 cup sugar until light in color and fluffy. Add 1/4 cup of the hot milk mixture to the egg-sugar mixture, whisking constantly, to temper. Be careful not to curdle the yolks. Once the yolks are tempered, add the egg-sugar mixture to the hot milk mixture and cook on medium-low heat for 2 minutes, while whisking.

3. Immediately transfer mixture to an ice bath. When it has chilled, strain it. Combine 2 cups of this ice cream base with 1 cup of the beer-syrup reduction. Refrigerate overnight for best results and then freeze in an ice cream machine, following the manufacturer's instructions.

Make the cake
1. Preheat the oven to 325°F (160°C).

2. Pour 1 1/2 cups boiling water over the oats and cover. Let the mixture stand for exactly 20 minutes before adding it to the cake batter.

3. Meanwhile, combine the flour with the baking powder, cinnamon, and mace, and mix well. Cream the brown and white sugars and butter together until very light and fluffy. Add the eggs and vanilla, scraping down the sides of the bowl as necessary.

4. Fold in the dry ingredients. Fold in the coconut and the oats.

5. Pour the batter into an 8-inch square baking dish. Bake for 50-60 minutes, until a toothpick inserted in the center comes out with just a touch of batter on it.

Make the icing
1. Melt the butter, brown sugar, and milk in a medium saucepan. Add the coconut and vanilla and combine. Refrigerate the mixture for 1 hour before spreading on the cake. Serve the cake with the ice cream.