Tofu substitute in no bake chocolate cake
This almost sounds like someone converted a classic mousse recipe to use tofu instead of dairy. My suggestion is to simply use any dairy with a consistency similar to your soft tofu, in the same ratio as the tofu. You can use cream cheese, if you are accustomed to the combination with chocolate. If you aren't, you might be unpleasantly surprised - in that case, take a less salty cheese, for example tvorog or ricotta. Fermented products will also work instead of cheese - you can use skyr or drained yogurt, maybe even creme fraiche.