Preheat the oven to 375 degrees. Line a baking sheet with parchment paper.
In a large bowl, cream together margarine and shortening until smooth.
Mix in sugar to combine, then incorporate lemon zest and juice. Add flour in small batches until well blended.
Drop teaspoon-sized balls of dough onto a baking sheet, about 1 inch apart.
Bake for 8 to 10 minutes until edges are set and slightly browned.
Remove the cookies from the oven and let them cool completely on the baking sheet before coating each cookie in powdered sugar.
To coat, use a fork to support each cookie and roll them in powdered sugar on both sides.
Store cooled cookies in an airtight container at room temperature.
