Add the peaches, tofu, sweetener, and vanilla paste to a blender.
Drain the soaked cashew nuts and add them to the blender as well.
Blend everything until nice and smooth.
These next few steps need to happen in quick succession because the agar-agar will start to set as soon as it begins to cool down. Here we go:
Pour the almond milk into a small pot and whisk in the agar-agar powder. Heat the milk over low heat and let it simmer for about 30 to 45 seconds, whisking continuously, until it starts to thicken.
As soon as this happens start up the blender with the peach mixture and, with the blender running, pour/scrape the agar-agar milk into the peach filling and blend everything until it is all nicely mixed. Then quickly pour the filling over your almond crust. Gently hit the spring form a few timed against your work top to get rid of whatever air pockets or bubbles may be hiding in the filling.
Put your cake in the fridge and allow it to set, 45 minutes to an hour.
Decorate with peach slices and fresh mint before serving, if you like, or serve as is.