Mist a 9- x 13-inch casserole dish with oil spray. Add the bananas and mash them up with a fork until smooth and creamy. Then add the Greek yogurt, milk, honey (or maple syrup), vanilla and eggs (you can crack the eggs right into the casserole dish but be sure to whip them with a fork before mixing into the entire wet batter).
Mix and mash all the wet ingredients together until it’s as smooth as possible; having some small lumps is okay.
Stir in the oats, cinnamon, baking powder, salt, and chopped peaches (reserve a small handful to sprinkle over the top before placing in the oven), and mix everything together, so the ingredients are evenly distributed. Sprinkle the reserved peaches over the top. Bake in oven for 45 to 50 minutes until the top is slightly browned and firm. NOTE: 45 minutes will yield a softer, more oatmeal-like consistency and 50 minutes will be firmer and cake-like. If you remove your pan at 45 minutes, let it cool and then decide you’d like it firmer, you can easily put it back in the oven for a few extra minutes.
Once baked, remove from the oven and allow to slightly cool on the counter for 5 minutes or so. Slice into large squares, add optional toppings and enjoy!
Notes
About the one-pan prep: • I mix everything directly in the casserole dish to avoid cleaning extra bowls (I’m always trying to cut back on cleaning!). However, if you prefer prepping the mixture in a separate bowl, you can certainly do so. First, add the wet ingredients and mix until smooth and well-combined. Then, add the dry ingredients. Once everything is blended, transfer the batter into your oiled casserole pan and bake in the oven as directed.For the yogurt: • You can use a peach-flavored or vanilla-flavored Greek yogurt. I prefer using nonfat or low-fat yogurt brands that are sweetened with stevia or monkfruit (without added sugar), such as Oikos Triple Zero, Oikos Pro or Too Good.Quick tips on the fruit: • 3 medium peaches will yield about 2 cups chopped. If using frozen, sliced peaches, be sure to chop them up into small pieces and then measure out your 2 cups.• Make sure to use ripe, juicy peaches for the best flavor, but if your peaches are a bit firm, you can microwave them for 20 seconds to soften them up before slicing. You can also use frozen peaches – just chop them up into small pieces before tossing them into the batter.• I also suggest using super-ripe bananas, as they’re easiest to mash and lend natural sweet creaminess to your finished bake. If you’re banana isn’t overly ripe and you’re having difficulty mashing it, microwave for 20 to seconds to soften it upIngredient swaps: • You can use canned peaches in syrup for this recipe! Here’s how to make it work: Peaches: You’ll need two (15 oz) cans of peaches. Each can will give you about 1 cup of chopped peaches, and the recipe calls for 2 cups for that perfect peachy flavor. Drain the peaches (but save that sweet syrup!) and chop them into bite-sized pieces.Sweetener: Since the syrup from the canned peaches is sweet, reduce the honey or maple syrup from 2 tablespoons to just 1 tablespoon. You might even find that you can skip the extra sweetener altogether. Mix your reserved syrup into the batter when the instructions say to add the milk and honey.Milk: To balance the extra liquid from the syrup, use only ¾ cup of milk instead of the full 2 cups. This adjustment ensures the perfect consistency.• You can replace the bananas with 1 cup unsweetened applesauce or canned pumpkin puree.• Any milk can be used. I typically use almond milk and that is what I included in the nutrition information.• For a dairy-free version, use almond milk and coconut or soy yogurt.To prep ahead: • You can prep the batter in the casserole pan the night before, cover and refrigerate, and bake the next morning as directed.Storage: • Store leftover oatmeal bake in the fridge for up to 3 days or freeze individual squares for 2 months; reheat in the microwave or thaw on the counter and warm in the oven.Nutrition info: • I based the nutrition information on 6 servings using almond milk and no-sugar-added, peach-flavored Greek yogurt.Dietary considerations: • If you’re following a gluten-free diet, be sure to carefully read the packaging for each ingredient, especially the oats (look for brands that are certified gluten-free). While these foods are inherently gluten-free, gluten can sometimes be added during processing for a variety of reasons, including for flavor and consistency.• If you’re looking to make this recipe nut-free, please be sure to use a nut-free milk.
Nutrition information is calculated using a leading industry software. That being said, brands can vary, and there may be slight fluctuations in the numbers.