Add walnuts to a food processor and pulse until a semi-fine meal is achieved.
Then, with the processor running, drop in dates one at a time through the spout until the mixture resembles a dough. It should hold form when squeezed between two fingers. This will take anywhere from 7-12 dates, depending on their size (as original recipe is written // adjust if altering batch size).
Line a standard pie or tart pan, or several 4 3/4-inch tart pans (I bought mine here) with parchment paper. Divide crust between the pans and press using your hands to form a uniform crust. Place another piece of parchment paper on top and use a glass to get it more even and firmly pressed into place. It doesn't have to be perfect. Set in freezer to chill.
Add drained tofu, lemon juice, vanilla, and sweetener of choice to blender and blend until creamy and smooth, scraping down edges as needed. I used half date caramel and half agave. Adjust flavors to desired level of tartness/sweetness.
Remove crust from freezer and top with lemon filling. Chill to set - at least 2-4 hours - and then top with fruit just before serving. You could also serve with coconut whipped cream to send these over the top.
Store leftovers in the fridge for up to a few days. Transfer to freezer for longer-term storage.
*Although I opted for three mini tarts, you could also just make this recipe in one big pie pan if you don't have tart pans. *Tart inspired by/roughly adapted from Oh, Ladycakes - the vegan tart queen. *Nutrition information is a rough estimate calculated using 4 3/4-inch tart pans.