Preheat the oven to 350 F and prepare a 9 inch pan with parchment paper and set it aside.
In a small bowl, stir together the streusel ingredients using a fork. Chill until ready to use.
In a mixing bowl, stir together the dry cake ingredients: flour, sugar, baking powder, salt and spices. Add in the remaining wet ingredients and stir until no dry spots remain. Fold in walnuts. Pour half of the mixture into the prepared pan.
In another bowl, stir together the cinnamon swirl ingredients and sprinkle over the cake batter in the pan. Top with remaining batter, dropping in dollops and then carefully smoothing over the cinnamon swirl.
Sprinkle the chilled streusel over the cake and bake for 35-45 minutes. A toothpick should come out clean when inserted into the center. Let cool.
Stir together the glaze ingredients and drizzle over the coffee cake and serve!
Notes
The cake is best if stored lightly covered at room temperature for 2 days or in the covered in the refrigerator for 5 days.Gluten free all purpose flour can be replaced with: all purpose flour or whole wheat flour.Cake can be topped with fresh fruit if desired.