Instructions:
1. Preheat oven to 350°F.
2. In the bowl of an electric mixer, cream butter, Crisco, and sugar until fluffy. Add vanilla, egg, and lemon zest; mix.
3. In a separate bowl, sift together flour, salt, and baking soda. Add dry ingredients to mixer and combine. Add milk and lemon juice, and stir until completely incorporated.
4. Roll dough into tablespoon-sized balls and place on a greased baking sheet.
5. Bake for 10-12 minutes, until cookies are just beginning to turn golden on the edges. Remove from oven and cool completely before frosting.
6. To make the frosting, beat butter and cream cheese until smooth and well mixed. Add vanilla. Add powdered sugar and salt. Stir. Mix in fresh lemon juice until the frosting reaches a spreadable consistency.