Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan.

In a large bowl, combine the all-purpose flour, whole wheat flour, granulated sugar, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt.

In another bowl, whisk together the pumpkin puree, vegetable oil, eggs, vanilla extract, and cooled coffee until well combined.

Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix.

Fold in the chopped walnuts or pecans gently.

Pour the batter into the prepared baking pan, smoothing the top with a spatula.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, remove from the oven and let it cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

In a small bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth to make the icing.

Once the cake has cooled, drizzle the icing over the top and allow it to set before slicing.