Preheat the oven to 375 degrees F. Line the bottom of a 26 cm (10") spring form cake pan with parchment paper. Use scissors to cut the parchment paper to size. Grease the parchment paper and the sides of the pan.

Wash the rhubarb stalks and dry them, then cut them into 2 cm chunks, cutting the large stalks in half before cutting in chunks. Do not peel the rhubarb. Mix the rhubarb with 3 tbsp of the sugar and spread evenly onto the bottom of the cake pan.

Cream the butter with the sugars and the vanilla extract until very creamy. Add the eggs one at a time and beat until smooth. Sift the flour and baking powder together and then gently fold it into the creamed mixture until fully incorporated. Drop dollops of the dough evenly over the rhubarb, then spread the dough evenly over the rhubarb. This may not look like it's enough dough but it is!

Bake for 40 - 50 minutes or until golden brown on top and a toothpick inserted in the centre comes out clean. Place the cake on a cooling rack. Loosen the cake from the ring of the spring form pan by gliding a sharp knife around the perimeter of the cake, then remove the ring of the pan. Place another cooling rack upside down on top of the cake and carefully flip the cake upside down. Remove the cake pan bottom and gently pull back and remove the parchment paper. Allow the cake to cool before serving.

Serve with a dollop of whipped cream and/or a drizzle of strawberry sauce.