I want to bake an indulgent, ultra-soft chocolate kue tart and I need a clear, kitchen-tested roadmap to get there. The cake must come out noticeably lighter than a standard sponge, so the formulation has to include the right emulsifier or cake softener and show exactly how and when to fold it in... (Budget: $250 - $750 USD, Jobs: Baking, Food Safety, Troubleshooting)