Source: The Red Lion Inn Cookbook

3/4 cup margarine
2 cups granulated  sugar
3 eggs
1 egg yolk
3 1/2 cups flour
1 tablespoon plus 1/2 teaspoon baking powder
1 1/2 teaspoons salt
2 cups lemon pudding - from mix or can
3 tablespoons milk

Preheat oven to 350 degrees F.

Grease two loaf pans. In a large bowl, cream the margarine and sugar together thoroughly.

Add the eggs, one at a time, mixing well after each.

Sift the dry ingredients together and add them to the eggs. Add the lemon pudding and milk, and mix until very well blended.

Pour the batter into the prepared loaf pans. Bake at 350 degrees F for 40 to 50 minutes, or until a wooden pick inserted in the center comes out clean.