Prep an 8 inch springform pan (spray with nonstick coating, or rub with butter and dust with flour).
Combine flour, oatbran, baking powder, Splenda, cocoa, and salt in large bowl.
Combine applesauce, syrup, maple extract, water, soymilk, vanilla, tahini, and p.b. in medium bowl and mix well.
Add wet ingredients to dry and mix well.
Bake for 20 - 30 minutes (test with toothpick).
For the mousse:.
Process tofu, syrup, salt, vanilla, lemon juice, and p.b. until smooth.
Mix together soymilk and cornstarch in small bowl.
Heat water and agar in saucepan over low-medium heat, and bring to a gentle boil, stirring as the mixture thickens. When agar is dissolved and the mixture is pudding thick, add the soy milk and cornstarch. Stir until mix boils again and then remove from heat.
With processor on, add agar mixture to the tofu mixture in a thin stream.
When completely combined, pour mousse over cake.
Cover with plastic wrap and refrigerate until set (at least 6 hours, or overnight).
Optional: Make a ganache drizzle by mixing melted vegan chocolate with soymilk.