1Preheat oven to 350. Butter a 9x13 inch pan and set aside.
To make the crumbs combine all of the ingredients in a medium bowl with a spoon or your fingers until the mixture forms coarse crumbs; set aside.
2To make the cake sift together the flour, cinnamon, ginger, nutmeg, cloves, baking powder, baking soda and salt onto a sheet of waxed paper; set aside.
3In a large bowl, beat the butter with an electric mixer on high speed until light and fluffy. Gradually beat in the sugars, beating until very light. Change the mixer speed to medium and beat in the eggs, one at a time, beating well after each addition.
4Change the mixer speed to low and alternately beat in the flour mixture and buttermilk, beginning and ending with the flour mixture and beating just until blended. Spread the batter in the prepared pan. Scatter the crumbs over the top, pressing them lightly into the batter.
5Bake until the top of the cake is firm, the crumbs are crisp, and a skewer inserted into the cake comes out clean, 40-45 minutes. Cool in the pan on a wire rack. Dust with the confectioner's sugar before serving if desired.