Bright red, crisp stalks of rhubarb are available at the Farmer’s Market these days. Perfect for making rhubarb crumble, but I really didn’t want to turn on the oven while it was a humid 30°C outside, and our air conditioning was already blasting — so I cooked my first crumble in the slow cooker. We were thrilled with the results. This citrusy, rhubarb crumble was so good that we devoured it within two days!