Preheat the oven to 180°C (convection)
Melt butter and white chocolate together
Stir in black sesame paste
In a stand mixer beat eggs and sugar on medium high for 5-10 minutes until very thick
Add in sifted flour and black sesame powder and mix on low until just combined
Slowly pour in the melted butter mixture and mix until just combined
Transfer batter to a buttered oven safe dish
Bake in a hot water bath for 30 minutes until the top is firm but slightly brittle
Remove from oven and water bath and let cool slightly
Serve immediately
