Make raw sugar into caster sugar by processing on speed 9 for approximately 5-10 seconds. Set aside.
Place cream into TM bowl.
Insert Butterfly attachment and whip cream on speed 4 until thick. (Time will vary based on the freshness of the cream, the fresher it is, the longer it will take.)
Add eggs one at a time and blend in gently on speed 3-4. Add essence as well.
Remove Butterfly attachment.
Add flour and sugar. Pulse 4-5 times to blend. DO NOT OVERMIX.
Pour batter into spring form pan.
Place cut rhubarb stalks on top of batter. Sprinkle with second amount of sugar.
Process in steam oven for 40-50 minutes or until a skewer comes out clean.
While the cake is steaming, place all topping ingredients except almond flakes into TM bowl.
Blend together quickly for 20 seconds on speed 8.
Cook for 3 minutes on 80 degrees Celsius on stir.
Spread over top of steamed cake, sprinkle with almond flakes and either bake for 10 minutes in 180 degree oven or allow topping to set.
With custard or freshly whipped cream.