Preheat the oven to 350 degrees and grease two 1-cup ramekins or oven safe bowls.
Finely dice rhubarb, removing the outer stringy skin if necessary. Combine it in a bowl with the raspberries, oats, sugar, and lemon juice. Divide the mixture between the two ramekins.
In a separate bowl, use your fingers to combine the topping ingredients (oats, coconut oil, and salt). Divide the mixture on top of the fruit, pressing down slightly for an even topping.
Bake the ramekins for 30 minutes, or until the oats are lightly toasted and the fruit filling is bubbling.
Notes
Use certified gluten-free oats to ensure the crumble is gluten-free. This recipe can be cut in half for one serving instead of two.
Recipe by Uproot Kitchen at https://uprootkitchen.com/2015/04/20/raspberry-rhubarb-crumble/