For the rhubarb tart with coconut, place the butter cookies in a freezer bag and crumble with a meat mallet. Melt the butter slowly and mix it into the crumbled butter cookies.
Line a springform pan with baking paper, spread the butter crumbs in the pan and press firmly. Wash and peel the rhubarb and cut into small pieces.
Mix the remaining ingredients together well. Finally, fold in the rhubarb pieces. Pour the mixture into the springform pan, smooth it out and bake in a preheated oven at 160 °C (convection oven) for about 50 minutes.
Allow the rhubarb tart with coconut to cool in the pan, then portion and serve with a fresh mint leaf.