I've spent a good deal of time thinking about granola here on Serious Eats, and after countless experiments, I settled on the ultimate recipe long ago—my crispy buttermilk granola.
What sets it apart from other recipes is the astonishing amount of liquid it calls for, which gets ample time to soak into the rolled oats before they're baked in the oven. This makes the oats porous and crisp, tender from the inside out, and washes out their starch, creating all kinds of clusters and clumps. I think the recipe is perfect as is, but I'm always open to variations on a theme.
A while back, I started playing around with nondairy substitutes for the buttermilk, and while I wasn't content with any of the nut-based "milks" I tried, I found surprising success with an unusual ingredient: overripe bananas.
When mashed into a thick but smooth purée, bananas are able to hydrate the rolled oats (and other grains or seeds) in a similar way but with a bonus to flavor and nutrition.
As with my favorite banana bread, this recipe calls for pinches of cinnamon, cloves, and nutmeg to highlight the banana's natural flavor (along with a dash of salt and a splash of vanilla for an aromatic boost).
The idea isn't to make a heavily spiced granola, but rather to layer in sympathetic flavors and aromas that help the banana pop. This works, thanks to an essential oil called eugenol, which is common to banana, cinnamon, nutmeg, and cloves.
In addition to the rolled oats, I also add ground flaxseed, chia, and toasted wheat germ, for both their nutty flavor and nibby texture (not to mention their nutritional value).
It's a blend that adds a lot of character to the granola, but it is not essential from a structural perspective, so it's okay to leave it out or experiment with other ingredients instead. The important thing is to stick with the quantities suggested, so that new additions don't overwhelm the mix or affect it in unexpected ways.
After mixing everything together, I let the granola stand for about 30 minutes to fully hydrate the oats and other grains/seeds. It won't hurt the granola to sit out longer if that helps with timing—just don't rush the process; it takes time for the moisture to work its way to the center of each grain.
When the mixture is fully hydrated, I stir in toasted sugar for some subtle caramel notes and mellow sweetness, although plain white sugar works well, too (if added earlier in the process, the sugar will prevent the banana purée from soaking into the oats).
Once the sugar has fully dissolved, creating a light syrup around the oats, I stir in a bit of melted coconut oil. Refined or virgin oils work equally well, but I find the sweet and nutty aroma of virgin coconut oil to be a fantastic complement to the tropical banana. Not all brands have an equally potent aroma, however, so the effects will vary; after testing dozens of brands back during my coconut cake phase, I found that Vita Cocoa seems to have the clearest coconut flavor.
To bake the granola, I spread it into an even layer on a parchment-lined half-sheet pan, using a pair of forks to break up the larger clumps. These clumps will continue to break up during the stirring process later on, so do leave some big chunks here and there.
In order to drive off all the moisture without burning the granola, it's baked off low and slow at just 300°F. Here, it's important to know your oven; if it doesn't run true to dial, the granola may bake too quickly and brown faster than it can crisp, resulting in the strange dichotomy of burned but soggy granola.
To ensure the granola browns evenly, I toss and stir the mixture every 25 minutes or so, working to migrate the granola around the edges to the center and vice versa. I keep baking and stirring until it's crisp, dry, and well browned.
Thanks to the banana purée, the mixture will look much darker than you might normally expect from granola, but with ample stirring at 300°F, it won't burn. It's normal for the timing to vary, but it shouldn't take any more than two hours.
Meanwhile, I season a mixture of toasted pumpkin seeds, macadamia nuts, walnuts, and pecans with a little oil and salt, and then stir in a blend of dried fruit.
This particular batch includes tart cherries, mango slices, and blueberries.
To help keep the granola more homogenous, I like to toss it with the fruit and nuts while warm, which seems to help everything stick together a little more.
Of course, any blend of dried fruits and nuts will do, so use whatever you have on hand, but the tropical vibe of macadamia nuts and mango pair especially well with banana, so they're worth seeking out.
Whatever mix you choose, when everything's all tossed together, spread it back out on a fresh baking sheet to cool.
Increasing the surface area of the granola helps it cool faster and prevents any part of it from sweating or softening with steam (as it might in a deep bowl).
The cooling process will take about 45 minutes, but the granola shouldn't be left out indefinitely. As soon as it's cool, transfer it to bags or jars to keep it crisp. Or, if you're feeling fancy, the cooled granola can be spiked with one last layer of fruit flavor: freeze-dried bananas.
Admittedly, the astronaut ice cream-like texture isn't for everyone, so don't feel this is in any way a necessary step. But for those who enjoy its shattering crunch, freeze-dried banana slices can be a lot of fun.
Despite all the bananas involved, the granola isn't over-the-top bananas. It's nuanced and delicate, an intriguing thread of fruit flavor that sets it apart from other recipes.
For me, it's the perfect alternative to banana bread for using up overripe bananas and a wonderful way for making a tender yet crunchy nondairy granola.
Like the original, this granola will keep for weeks in an airtight container at cool room temperature, so you can savor it for breakfast one morning at a time (or try a handful over banana pudding for dessert).