Enjoy a warm, hearty breakfast with Strawberry Rhubarb Baked Oatmeal – sweet, tangy, and ready in minutes.
Lightly spray a 9 x 9" ceramic baking dish and lay the thinly sliced banana in a single even layer across the base. Arrange the banana slices so they just overlap — they form a sweet, soft base that will caramelize a little in the oven. This step is quick and simple, done with a gentle, even touch so the banana slices lie flat and will later cradle the fruit filling.
In a large bowl, combine hulled, quartered strawberries and 1/2-inch pieces of rhubarb. Add the honey and sprinkle the cornstarch over the fruit, then toss until every piece is glossy and lightly dusted with starch; you should see the berries glistening and the rhubarb pieces coated so they will thicken into a jammy filling as they bake. Spoon this vibrant ruby mixture evenly on top of the banana layer in the prepared dish so the fruit sits in a compact, colorful bed.
In a medium bowl, stir together the oats, half of the slivered almonds, baking powder, cinnamon, and a pinch of salt. The dry mix should smell faintly of cinnamon and have a coarse, crumbly texture from the oats and almonds — a grainy scaffold that will transform into a crunchy top once it meets the wet ingredients.
Whisk the remaining honey with the milk, the egg, and vanilla until smooth and slightly frothy. Pour the wet mixture into the dry oats and stir until the oats are evenly moistened; the texture becomes a loose, custardy oat batter that clings to the oats but still has visible flakes. Pour this oat batter over the fruit layer in the baking dish, smoothing gently so it spreads over the strawberries and rhubarb. Finish by sprinkling the remaining slivered almonds across the surface to create a crunchy golden top when baked.

Bake the assembled dish until the top is golden brown, the almonds are toasted, and the oat center has set — about 40 minutes; you’ll notice the fruit bubbling slightly at the edges and the top forming crisp, nutty highlights. Let it rest briefly, then serve warm directly from the same 9 x 9" ornate white ceramic baking dish so the rectangular shape and glossy fruit pockets are preserved.
