Method

1. Crumble
   Place all ingredients in a bowl and rub together until you have a crumble. Spread out on a tray and bake this in the oven at 170C until golden brown. Then leave this on the side to cool down.
   When it is cold place on a chopping board then run your knife though the mix until you have small pieces.  
   
2. Rhubarb
   Cook the rhubarb in a pan until soft then blend until smooth.
   Strain, then place the rhubarb juice into a clean pan and reduced by half.
   Add the cornflour and sugar to the rhubarb, and cook the cornflour out.
   After this pour into a tray and leave to cool.
3. Soufflé
   Whisk the egg whites until they start to aerate. Add the sugar in three parts.
   Once you have a firm egg whites mix, fold in 250g of your rhubarb base.
   Brush the inside of your soufflé mould with butter and coat in sugar - remove any excess. 
   Spoon the soufflé mix into the mould. Once full, tap on to a towel to remove any air pockets.
   Using a plate knife flatten the top and run your thumb around the top of the mould. 
   Cover the top with the crumble and bake in the oven at 175C for 8 1/2 minutes.
4. To serve
   Turn out the soufflé and serve with the broken up crumble and vanilla ice cream.