Preheat oven to 375 degrees F (190 degrees C). Grease and flour a 9x5 inch loaf pan.
Sift together flour, baking powder, cloves, cinnamon, allspice, baking soda, and salt in a bowl. Set aside.
In a large bowl, cream the butter and brown sugar until light and fluffy. Add egg and beat well. Add flour mixture alternately with beer and mix well to combine. Fold in the chopped walnuts.
Pour into a 9x5 inch loaf pan. Bake 40 to 50 minutes in the preheated oven, or until a toothpick inserted into the cake comes out clean.
