In a medium sized bowl add the ingredients for the crust. The flour, butter, oatmeal, brown sugar and salt. Mix until crumbly. Put half of the mixture into a greased 9 by 8 inch baking pan. Lightly press the mixture into the pan. Set aside the remaining mixture.
Filling
Combine the soft cream cheese and the sugar in the mixing bowl. Mix on medium speed until smooth. Add the egg, cinnamon and nutmeg and vanilla. Mix well. Pour mixture over crust.
Rhubarb
Using a microwavable bowl, add the rhubarb and 3 tbsp of sugar. Microwave on high for 1 minute. Remove and stir. Microwave for an additional minute and stir. Let cool for 5 minutes. Drop by the scoopful onto the filling. Use a knife and make a few swirls through the filling.
Topping
Top with the remaining crust mixture.
Bake time
Bake in a 350 degree oven for 40 minutes. Remove from oven and let cool. Store in refrigerator.