Lightly butter the inside of 6-8 oven proof cups and place them on a baking sheet lined with non-stick aluminum foil.
First make the topping. In a medium bowl, stir together sugar, flour, oats, brown sugar, lemon zest, cardamom and salt. Cut in the butter with a pastry cutter until completely blended.
Then make the fruit filling. In a large bowl, blend together the sugar and lemon juice. Then add the chopped rhubarb and strawberries, stirring to coat. Mix in the cornstarch and stir to thoroughly mix again. Finally, sprinkle over the Grand Marnier and stir to mix all of the ingredients together.
Divide the fruit mixture in between the prepared cups.
Divide the oatmeal crisp topping overtop of each cup of fruit.
Place the cups on the foil covered baking sheet.
Bake for about 35 to 40 minutes, until the filling is bubbly and the topping is browned. Allow to cool slightly then top with a scoop of ice cream.
Recipe by Just a Smidgen at https://justasmidgen.com/2012/04/16/there-is-no-harm-in-repeating-a-good-thing-plato/