While the cakes are baking, make the filling.
Tofu based creams must be pureed until absolutely smooth and creamy. If properly made, there will be absolutely no taste of tofu.
Make sure you've prepped the ingredients as stated in the list:
Simmer the tofu in a pot of water for 5 minutes.
Dissolve the arrowroot in the soy creamer.
Crumble the tofu into a food processor and process for 1 minute.
Add the oil and process 1 minute.
Add the rest of the ingredients except the arrowroot (which is now mixed with the soy creamer), and process 3 to 4 minutes, until the mixture is very smooth and creamy.
Stop the processor a few times and clean the sides of the bowl with a rubber spatula.
Stir the dissolved arrowroot to release any starch that has settled to the bottom.
Pour the arrowroot mixture into a small saucepan and cook, whisking frequently over medium heat until the mixture reaches a full boil. It will be very thick and gummy. Immediately remove the saucepan from the stove.
Add the thickened arrowroot to the rest of the filling ingredients and pulse to incorporate.
Process until the filling is smooth.
Spoon the filling into a container.
Cover and refrigerate for 2 hours or longer to allow the flavors to blend.