Line the bottom of a 9" springform pan with parchment paper. To do that, remove the ring and cover the bottom with parchment paper; Fold the excess paper back under the plate and, while holding it in place with one hand, put the ring back in its position with the other hand. Bring the excess paper back from under the pan but do not cut it off.
Combine the granola, coconut, chia seeds and melted coconut oil in the bowl of your food processor. Process until reduced to fine crumbs and press firmly at the bottom and slightly up the side of the prepared pan. Set aside.
FOR THE CHEESE FILLING
Start by placing the sheet gelatin to soak in a large bowl filled with icy cold water.
Combine the ricotta cheese, sour cream (or plain Greek yogurt), avocados, honey, matcha powder, vanilla extract and salt in the bowl of your food processor. Process until the mixture is super smooth and creamy and completely lump free, about 3 minutes. Stop the motor to scrape the sides once or twice to make sure that every last bit gets incorporated.
Warm the coconut milk in the microwave or over low heat until barely just warm to the touch. Remove the sheet gelatin from the water bath and squeeze between your hands to remove as much water as possible. Add gelatin to the warm coconut milk and stir until fully dissolved.Pour this into the cheese mixture and resume mixing until it's well incorporated.
Pour into the prepared crust, spread evenly and all the way to the edge then put the cake in the refrigerator until completely set, at least 6 hours but preferrably overnight.
THE FINISHING TOUCH
Once set, put 2-3 tablespoons of matcha powder in a small fine meshed sieve and dust the entire surface of the cake with it.
Carefully remove the cake from the pan and place it on a cake plate, then sprinkle a little bit of shredded coconut around the edge, if desired.
Keep refrigerated until ready to serve. Leftovers will keep in the fridge for about a week.