Strawberry-rhubarb is a classic flavor combination in the baking world for a reason--there’s something about that balance of sweet and tart ruby-red fruit that makes its fans anxious for spring to roll around, when strawberries and rhubarb are at their best. If you’re using fresh rhubarb, remove every bit of the leaves because they are toxic. If you’re using frozen sliced rhubarb, be sure to thaw and drain it well. The almond flour here is optional, but it does a great job soaking up any juices that may otherwise leak out while lending the filling a mildly nutty flavor.