Preheat oven to 325ºF and adjust rack to middle position. Place all the batter ingredients in a food processor or blender and blend until smooth. Pour batter into a buttered 8 x 8 - inch baking dish. Wipe out food processor bowl with a paper towel or cloth. Place nuts, cinnamon, honey and butter in the bowl of a food processor. Pulse until nuts are coarsely chopped and ingredients bind together. Drop spoonfuls of topping over batter and then using a butter knife, swirl the topping into the top layer of the batter. Bake for 40-45 minutes until golden brown.
Let cool for 20 minutes. Cut and serve. Coffee cake is best served the day it is prepared.