Preheat the oven to 180ºC/350ºF.
Line a medium round or squared cake pan with parchment paper.
Place the rhubarb stalks on the bottom of the pan and brush them with maple syrup, saving the rest for later. Cook in the oven for 10 minutes and remove.
In a large bowl whisk the sugar with the oil for 2 minutes. Add the egg until the batter starts to bubble.
Add in the yogurt and vanilla extract and combine.
In another bowl, combine the rice flour, almonds, baking powder and salt and slowly add to the batter, beating until completely blended. The batter will be thick.
Carefully pour the batter on top of the rhubarb and bake for 30 minutes.
Remove from oven and let cool in the pan for 30 minutes before turning it upside-down and carefully removing the parchment paper.
Brush the remaining maple syrup on top before serving.