In a medium bowl, whisk together the flour, baking powder and salt. Set aside.
In a large bowl, rub the lemon zest into the sugar with your fingertips until fragrant. Add the dairy free butter and beat for 2 minutes until fluffy.
Beat in the egg, dairy free ricotta, lemon juice and vanilla until smooth and creamy.
Add the dry ingredients and mix on low speed just until combined. Cover the soft dough and chill for 20 minutes so the cookies bake up tall and pillowy.
Preheat the oven to 375°F and line two baking sheets with parchment paper. Drop 2 tablespoon mounds of dough about 2 inches apart.
Bake for 13-15 minutes, until the tops are set and the bottoms are lightly golden. Cool on the sheet for 5 minutes, then move to a wire rack to cool completely.
For the glaze, whisk together the powdered sugar, lemon juice and lemon zest until thick but pourable. Spoon about 1 teaspoon over each cookie, spread it to the edges and let it set for 1 hour.