Preheat the oven to 350°. Grease a pie pan with coconut oil. To a food processor, add the flour, 2 tbsp sugar, ¼ tsp salt, and 5 tbsp cashew milk. Blend on low until the combined. Add the cold butter 1 tsp at a time until the dough is wet and starts to stick together. Press the dough into the pie pan, covering the bottom and the sides. Bake until golden brown, about 20 to 25 minutes. Remove from the oven and let cool.
Rinse the food processor. Zest the lemons. To the food processor, add the silken tofu, lemon juice, ½ cup sugar, cornstarch, 3 tbsp cashew milk, ¼ tsp salt, and 2 tbsp lemon zest. Blend until smooth, about 2 to 3 minutes. Once the crust has cooled, add the lemon tofu filling. Bake until firm and the edges are browned, about 40 to 45 minutes.
Drain the liquid (aquafaba) from the garbanzo beans into a large bowl, reserve the beans for another use. To the large bowl, add the cream of tartar, vanilla powder, 2 tbsp lemon zest, and sugar. Mix the aquafaba on high speed until it resembles a thick whip cream, about 15 to 20 minutes.
Dollop the meringue on top of the cooked pie. Bake for 5 to 8 minutes, until lightly browned. Let the pie cool and chill if preferred before cutting. Enjoy!