Preheat the oven to 350℉ and line two baking sheets with parchment paper. Set aside.
In a large bowl, combine the cake mix, baking powder, vegetable oil, lemon zest, and eggs until a thick batter forms.
Use a cookie scoop to scoop dough onto the baking sheets, leaving at least 2 inches between cookies.
Bake for 8-10 minutes, until the edges are set. If using a large cookie scoop, the cookies may need 12-14 minutes for the edges to set. Remove to a cooling rack and cool completely.
While the cookies are cooling, prepare the icing by whisking together the powdered sugar, lemon zest, lemon juice, and cream.
When the cookies are completely cooled, scoop about 2 teaspoons of the icing onto the center of each cookie, letting it pool on top and then run down the sides a bit. Let the icing form a crust before serving.