Preheat oven to 350°F (175°C)
Combine crushed graham crackers, 2 tbsp sugar, and melted butter until crumbly
Press mixture firmly into a greased 9×13-inch pan using a rolling pin
Refrigerate crust 15 minutes while oven preheats
In bowl, whisk 4 tbsp sugar, eggs, remaining 12 tbsp lemon juice, and 1/8 tsp salt until smooth
Pour filling over crust and bake 22-24 minutes until set
Cool completely on wire rack
In separate bowl, whisk coconut milk and soy milk
Chill filled bars 2 hours in fridge
Spread whipped topping over chilled filling
Dust with powdered sugar before serving
Cut into 24 bars using sharp knife