Preheat the oven to 350 degrees.

Using an electric mixer , mix the eggs, oil, sugar, and pumpkin together until smooth.

In another bowl, whisk the flour, baking soda, baking powder, salt, cinnamon, cloves, allspice, and ginger together.

Add the dry ingredients to the wet ingredients and continue beating until combined.

spray a 13 x 9-inch pan. Pour the batter into the pan and smooth it until it is level. Bake for 30 minutes or until a toothpick inserted in the center comes out clean.

Cool in the pan on a wire rack. Frost the cake.

To make the frosting:.

Beat the butter in a small bowl until it is fluffy. Add the zest. Gradually add the powdered sugar.

Beat in enough milk to reach the desired spreading consistency.

Cut it into bars to serve.