1. Preheat oven to 350 degrees F.
2. Prepare crust. In a medium bowl, mix flour, sugar, granola cereal, and butter until crumbly. Press into an ungreased 9-by-9- inch pan. Bake 17 to 20 minutes at 350 degrees F. Crust should be dark golden brown.
3. Prepare rhubarb filling. In a large bowl, combine yolks, cream, vanilla, sugar, salt, and flour. Stir with a spoon or whisk until well combined. Stir in rhubarb.
4. Pour rhubarb filling over prebaked crust. Bake for 40 minutes.
5. Prepare meringue topping. In a clean, medium bowl, beat egg whites on medium-high speed. When soft peaks begin to form, sprinkle in sugar and continue beating until stiff.
6. Lower heat to 300 degrees F. Remove rhubarb from oven. Pile meringue onto rhubarb. Smooth top with a rubber spatula, making small peaks. Bake an additional 15 to 30 minutes, until meringue is soft but firm and peaks begin to turn golden brown. Remove from oven and let rest for 15 to 20 minutes before serving. This dessert is good warm, room temperature, or cold.
Source: Hannaford fresh Magazine, March - April 2008