First, you’ll need to preheat the oven to 325 degrees Fahrenheit.
Shred the zucchini and let the excess water 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.
Mix the flour, baking soda, cinnamon, salt, and baking powder in a separate bowl.
If the zucchini is dripping and soggy, squeeze out the excess liquid. You want the tiniest bit of moisture in the zucchini, but you don’t want it dripping wet. Then stir the zucchini into wet ingredients.
Mix the wet and dry ingredients 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 non-stick baking spray, preferably one which has flour mixture added to it.
Pour half of the batter, over two cups, 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 time is 55-60 minutes or until a toothpick comes out moist but clean.
Cool on a wire cooling rack for 10 minutes, then invert onto a serving plate. Use a rubber spatula to help coax it out, if necessary.
Allow the cake to cool completely.
To make the icing, mix the confectioner’s sugar and cinnamon together in a medium-sized mixing bowl.
Add the vanilla and 3 tablespoons of half and half until a smooth glaze forms.
Add additional half and half, one teaspoon at a time, until it’s thick but slightly pourable.
When the cake cools completely, drizzle the icing slowly and evenly around the top of the cake while turning the serving plate. The icing should be thick enough that it doesn’t pool at the bottom but thin enough to slowly drip down the indentations on the sides.