This roasted rhubarb apple crisp recipe is so simple – with only 6 ingredients and minimal prep time. The crisp topping is based on oats, and uses oat-flour from blended oats. It is free of refined flour and refined sugar, and has 5 grams of fibre per serving.
I love roasting the rhubarb first to help save on prep time. In a conventional rhubarb crisp, the rhubarb and apple are cooked on the stovetop first, to break down prior to putting them in the oven with the oatmeal topping. By baking the rhubarb and apple first you cut back on dishes and also time spent in the kitchen. This is one of my favourite crisp toppings – a flour-free crisp, which I love using on all my crisps, such as on this Healthy Oat and Honey Cranberry Crisp.
Fibre helps to lower our blood sugars, cholesterol levels and helps to keep our gut bacteria nice and happy. I love sharing high-fibre desserts, like these Seedy Peanut Butter Oatmeal Cookies as alternatives to recipes based on white flour. The crisp topping is based on high-fibre oats, I like adding a little bit of coconut flakes for texture, but any nut or seed can be used as well.
Diabetic Friendly Crisp
This crisp is sweetened with honey which has a lower glycemic index than regular sugar, making it a better choice for blood sugar levels. It is also flour-free, and instead uses oats that have been ground up into ‘oat-flour’. Oats are not only a high-fibre replacement for regular flour (like in these Three Ingredient Banana Pancakes), but they are also a great low glycemic index choice. This crisp contains 32 grams of net carbs, making it a suitable diabetic dessert when served with some high-protein Greek yogurt.
Coconut oil is an easy replacement for butter and adds to the flavour of the coconut, which goes so nicely with the rhubarb and apple combination. Serve it with some dairy-free ice cream, such as coconut ice cream.
Making A Sweeter Crisp
I love the tartness of rhubarb and therefore do not add additional honey to the roasting rhubarb and apple. If you prefer a sweeter crisp, add 1 tablespoon of additional honey to the rhubarb and apple before roasting.
How To Make Oat Flour
Use a small blender or food processor to make the oat flour. When you are measuring out whole oats you will measure out more than the quantity of oat flour you need. As an example, for this recipe, you would measure out about 1/3 cup of whole oats to make 1/4 cup of oat flour. This is because the oats become more condensed after blending.
Using Coconut Flakes
I used large coconut flakes for texture, but feel free to use the smaller coconut flakes. Choose unsweetened coconut flakes.
Leaving The Skin On The Apples
I like to leave the skin on the apples to increase the overall fibre of the dish, making it a better choice for blood sugar levels. The skin and the flesh of the apple just under the skin is also where many of the important nutrients are.
Making It Gluten-Free
This crisp is naturally gluten-free because it does not use regular flour. If you are serving it to someone who has celiac disease, just make sure that the oats are certified gluten-free, as oats can potentially become contaminated during processing.
Making It Dairy Free
This crisp uses coconut oil in place of butter for a dairy-free alternative. For strict vegans who avoid honey, replace the honey with 1/3 cup of maple syrup. Serve it with some dairy-free ice cream or yoghurt in place of regular ice cream or yogurt.
Alternatives to Coconut Flakes
The coconut flakes add some texture and fibre to the crisp topping and if you don’t have coconut flakes on hand, you can substitute them out for some nuts. Try adding some chopped pecans or almonds to the crisp topping before baking.
What To Serve This Rhubarb Apple Crisp With
I love serving this crisp with some coconut-based ice cream. For those who have dairy, they might choose some plain yogurt, Greek yogurt, or regular ice cream. The high protein content of Greek yogurt helps to reduce any blood sugar spikes from the fruit, honey, and oats by slowing down the digestion of these carbohydrates into sugar.
Making A Rhubarb Strawberry Crisp
Strawberries do not need to be roasted ahead of time. If substituting in strawberries for the apples, roast the rhubarb as per recipe directions and then add 3 cups of halved strawberries and top with crisp topping and bake for 20 minutes.
Making A Rhubarb Blueberry Crisp
The same with strawberries, blueberries do not need to be roasted ahead of time. Add 2 cups of blueberries after the rhubarb has been roasted, and then top with the crisp topping.
Making A Rhubarb Saskatoon Berry Crisp
If you’re lucky enough to get your hands on saskatoon berries, you can substitute in 2 cups of Saskatoon berries for the apples. Add the berries to the already roasted rhubarb. I suggest drizzling over 1 tablespoon of additional honey to sweeten the fruit mixture, before adding the crisp topping.
More Recipes Featuring Oats
Oats are a great base for desserts as they add beneficial soluble fibre and can replace refined flours in many desserts. Here are a few of my favourite dessert recipes featuring oats:
- Seedy Peanut Butter Oatmeal Cookies
- Easy Almond Butter Chocolate Chip Cookie
- Tahini Coconut No-Bake Energy Balls
More Healthy Dessert Recipes
Healthy dessert doesn’t need to be boring. Here are some of my favourite healthy dessert recipes:
- Raw Chocolate Date Bar
- Three Ingredient Peanut Butter Cookies
- Raw Chocolate Brownies with Caramel Icing
Roasted Rhubarb Apple Crisp | 6-Ingredients, GF
- 5 stalks rhubarb
- 5 small apples or 3 medium
- 1 cup oats traditional
- 1/4 cup oat flour (or 1/3 cup of traditional oats for making flour)
- 1/4 cup honey (or 1/3 cup of maple syrup for a vegan version)
- 2 tbsp coconut oil
- 1/4 cup coconut flakes large, unsweetened
- Preheat the oven to 350°F. Grease a baking sheet with coconut oil or line it with parchment paper.
- Wash the apples and slice off the four quadrants and dispose of the core. You can leave the skin on as this contributes to more fibre. Dice the apple into small 1/2 inch pieces and place on the baking tray.
- Wash the rhubarb and remove any discoloured ends. Cut the rhubarb into small pieces - if the stalks are thick you may have to slice them lengthwise first, and then dice them. Add the diced rhubarb to a baking tray on top of the apples.
- *You have the option here of adding an additional 1 tablespoon of honey (or maple syrup) on top of the diced fruit for a sweeter crisp. I do not add honey to the fruit.
- Place the baking tray of chopped apple and rhubarb into the preheated oven and bake for 15 minutes.
To Make The Crisp Topping
- While the fruit is baking, make the crisp topping. First, if you are making the oat flour at home add 1/3 cup of whole oats to a small blender and blend until a fine flour is formed. If you are purchasing oat flour you can skip this step.
- Next, melt the coconut oil on the stovetop. Add the melted coconut oil to the 1 cup of oats, 1/4 cup of oat flour, 1/4 cup coconut flakes and 1/4 cup of honey (or 1/3 cup of maple syrup) and mix until well combined.
- When the fruit is finished baking remove it from the oven. Add the crisp topping evenly over the roasted fruit. Return the baking tray to the oven and bake for an additional 20 minutes.
- You will know the crisp is done when it is nice and golden on top. Let cool slightly before serving. Serve with some coconut-based ice cream or yogurt. Store leftovers in the fridge.