Preheat the oven at 180°C (350° F).
In a blender place rolled oat, almonds, dates, a pinch of salt and vanilla extract. Blend until all crumbled (crumbles size depends on your personal taste).
Add melted coconut oil and mix well.
Evenly spread the mixture into a 19-20 cm round hinge mold forming a base and sides roughly ½ cm thick.
Bake for 10 minutes.
Blend vegan cream cheese, soy whipping cream, icing sugar, tapioca, vanilla extract, syrup and lemon juice until smooth and creamy (around 1 minute).
Pour the mixture over the baked crust, spread it evenly and bake for 50-60 minutes until the center of the cheesecake is still a bit wobbly but firm (to prevent the surface and the edges to go brown, cover the mold with some foil).
Cut the rhubarb into diamond shapes, align the pieces onto a tray and bake for 10 minutes (@ 180°C).
Once the cake is ready allow it to cool completely at room temperature (do not open the mold ring!).
Decorate the top of the cheesecake with rhubarb pieces. For the red jelly simply stir together agar agar powder, brown sugar, food colouring (optional) and water. Microwave at 800W for 1-1:30 minutes.
Pour the jelly over the cheesecake making sure to fill every space/gap in between the rhubarb slices. Allow to cool for at least 2 hours in the fridge before serving.