Shred the zucchini and let it drain in a colander while you begin to prepare the cake.
In a large mixing bowl, beat together the eggs, sugar, oil, and vanilla with a hand or stand mixer.
In a separate bowl, mix together the flour, baking soda, cinnamon, salt, and baking powder.
If the zucchini is still dripping and soggy, squeeze out some of the extra moisture. You want the tiniest bit of moisture in the zucchini, but you don’t want it dripping wet. Then stir the zucchini into the wet ingredients.
Mix the wet and dry mixtures together, just until combined.
Gently fold the nuts into the batter.
Mix the sugar and cinnamon together in a small mixing bowl. You will use this to create the swirl in your cake.
Spray the Bundt pan well with a non-stick baking spray, preferably one which has flour added to it.
Pour half of the batter into the prepared pan. Sprinkle the top of this layer with the cinnamon swirl mixture, then add the other half of the batter as evenly as possible.
Bake for 55-60 minutes, or until a toothpick comes out moist but clean.
Cool the cake and pan on a wire cooling rack for 10 minutes, then invert the pan onto a serving plate. Allow the cake to cool completely.
To make the icing, mix the powdered sugar and cinnamon together in a medium-sized mixing bowl. Add the vanilla and 3 tablespoons of half and half. Mix until a smooth glaze forms. If necessary, add additional half and half, one teaspoon at a time, until it’s thick but slightly pourable.
When the cake is completely cool, drizzle the icing slowly and evenly around the top of the cake.
Serve or store.
Notes
Store this cake in an airtight container at room temperature for 3 to 4 days. You can also freeze the entire cake, or pieces of it, wrapped well with plastic wrap and then put it into freezer-safe bags for 2 or 3 months for best quality. Bring the cake back to room temperature before eating.