This dark, moist coffee cake can be made with either whole wheat flour or spelt, an ancient variety of wheat. Spelt behaves like whole wheat flour, but has a wonderfully mild, nutty flavor; try substituting it for whole wheat in your favorite recipes.
Preheat the oven to 350°F. Lightly grease an 8" square or 9" round cake pan.
Beat the butter and sugar together until smooth and lump-free.
Beat in the eggs one by one, until the mixture is thoroughly combined.
Whisk the baking powder, salt, and spices into the spelt flour. Stir half the flour mixture into the butter/sugar/eggs to combine. Stir in the milk, then add the remaining flour mixture, stirring to combine.
To make the topping: Gently beat all of the topping ingredients together until crumbly.
Pour the batter into the pan. Sprinkle the topping over the cake. Use a table knife or spatula to briefly and gently swirl it into the batter; you don't want to combine the two completely, just make a streusel swirl.
Bake the coffee cake for 35 minutes, or until a toothpick inserted into the center comes out clean. Remove the cake from the oven, and allow it to cool before cutting.
Store leftover coffee cake, well-wrapped, at room temperature for several days; freeze for longer storage.
