Keto Raspberry Crumble

I started making this raspberry crumble about five years ago, and it went through a lot of versions before I landed here. The early ones had soggy toppings, watery fillings, or just tasted like almond flour and sadness. This version holds up.

The topping is what makes it. I use a combination of almond flour, walnuts, pecans, and hemp hearts, which gives you layers of crunch that a single-nut topping can’t match. The hemp hearts add this subtle nutty chew that rounds everything out. I pulse it all in the food processor with cold butter until it looks like coarse sand with pebbles, and that uneven texture is exactly what you want. The bigger pieces toast up golden, the smaller bits get crispy, and none of it turns to mush.

For the filling, fresh raspberries break down into this thick, jammy sauce in the oven. I use xanthan gum as the thickener (not arrowroot, more on that in the how-to below) and just enough sweetener to balance the tartness without burying the fruit flavor. The raspberries do most of the work on their own.

I serve this warm with a scoop of keto vanilla ice cream or a pile of whipped cream. It’s also good alongside keto strawberry ice cream if you want to double down on the berry situation. Reheated the next day, it’s still solid. The topping crisps back up in a 300-degree oven for about 8 minutes.

One reader, Ashley, told me she tried six different low carb crumble recipes before landing on this one. Her words: “The topping actually stays crumbly instead of turning into a sad mush, and the raspberries don’t get watery.” That’s the whole point of this recipe. The filling stays thick, the topping stays crunchy, and it tastes like the real thing.

If you like fruity keto desserts, I also make a keto chocolate trifle that layers well with berries, and my almond flour cookies use a similar base if you want something more portable. But when I want something warm out of the oven with that fruit-and-crumble smell filling the kitchen, this is what I reach for.

The two things that make or break any fruit crumble are the thickener and the topping texture. I’ve tested both sides of this recipe more times than I should probably admit.

Thickener: use xanthan gum, not arrowroot. I tried arrowroot early on and it thickened fine in the oven, but as soon as the crumble cooled to room temperature, the filling thinned right back out. Xanthan gum holds at every temperature. One teaspoon is all it takes. A reader named Lynn confirmed the same arrowroot issue in her version, so this isn’t just my kitchen.

Topping texture: cold butter and a quick pulse. Cut your butter into small cubes straight from the fridge. Pulse in the food processor just until you see coarse crumbles with some bigger chunks still visible. If you over-process it into a fine powder, you lose the crunchy pieces that make this topping work. Think gravel, not sand. I use a similar cold-butter technique for my keto pie crust, and it works the same way there.

Freezing and make-ahead. I assemble the whole thing unbaked, cover tightly with foil, and freeze for up to a month. Bake from frozen at 350 degrees, adding 8-10 extra minutes. The topping still crisps up. You can also freeze baked leftovers and reheat in a 300-degree oven for about 10 minutes.

For a summer version, try mixing in fresh strawberries alongside the raspberries. I’ve done a half-and-half split that worked well, and it pairs nicely with keto strawberry shortcake kebabs or a scoop of strawberry sorbet for a full berry spread.