With rack in the middle, preheat oven to 350ºF.
Line a jellyroll pan (14.19" x 9.25" or 17.25" x 12.25") with parchment paper.
In a medium bowl, whisk 1.5 cup flour, 1 teaspoon cinnamon, 1/2 teaspoon ginger, 1/4 teaspoon nutmeg, 1 teaspoon baking powder, 1/2 teaspoon baking soda and 1/2 teaspoon salt.
In a standup mixer fitter with a whisk attachment (or hand-held mixer), on medium speed beat 1.25 cups sugar and 10 tablespoons butter until smooth, 3 minutes or so. Add 3 eggs, one at a time, beating well after each addition. Add 1 teaspoon vanilla.
Reduce speed to low, add shredded carrots.
Fold in the flour mixture. Add nuts.
Spread the batter on the jellyroll pan, smooth it out.
Bake 18-20 minutes, or until a toothpick inserted in the middle comes out clean. Turn the pan halfway through baking.
Transfer to a cooling rack and allow to cool completely in the pan.