I love rhubarb. The only problem is I can never get enough of it. This year a neighbor told me to “take all you want,” and I gratefully accepted. I felt a little ridiculous carrying armfuls down the lane, but I escaped without incident and returned home to bake a strawberry rhubarb coffee cake.
This coffee cake is straightforward. It has distinct layers—a base cake, a jam-like filling, more cake, and a crumbly topping—but it comes together quickly. It slices neatly and holds its shape, so it’s just as good as a snacking cake as it is for dessert.
The cake is sugar-free, gluten-free, and keto-friendly depending on portion size. It pairs beautifully with a scoop of ice cream or a dollop of whipped cream and has about 5 net carbs per serving (without added whipped cream).
Strawberry Rhubarb Jam Squares
The structure is simple: cake base, jam filling, another cake layer, and a crumbly topping. The texture is reminiscent of an old-fashioned coffee cake—moist and tender with a buttery crumb.
You don’t need much rhubarb to get a bright tart flavor. About 1 1/4 cups of chopped rhubarb—roughly two medium stalks—is enough for the whole recipe.
a bit about the rhubarb
Rhubarb can be tricky to source if you don’t grow it yourself. I have a small plant, but it won’t be ready for harvest for another year. Thankfully, friends and neighbors often share extras in early summer.
One season I even found frozen rhubarb in the supermarket frozen-foods aisle. It seemed seasonal, but it was a welcome find—I bought extra and kept an eye out for more. Frozen rhubarb is a convenient alternative when fresh is scarce.
Rhubarb is a good option for low-carb and keto baking; at about 3.3 net carbs per cup, it adds a bright, tart note to muffins, tarts, cakes, and preserves.
A bit about the coffee cake batter
Here are two handy tips for working with this batter. First, line a 9×9 square pan with two overlapping strips of parchment paper. This makes lifting the entire cake out of the pan effortless once it’s cooled.
Second, when spreading the top layer of batter over the jam, use the back of a spoon lightly coated with melted butter. Because the batter is thick and tends to cling to the spoon rather than glide over the jam, the buttery spoon helps spread it evenly without dragging the jam layer.
a bit about the jam filling
The low-carb jam filling is easy to make. Cook chopped rhubarb and strawberries with a granular sweetener and a splash of water over medium-high heat until the mixture thickens. To thicken, you can use chia seeds added after cooking, or a pinch of xanthan gum. Both work well—chia will leave tiny seeds in the jam, while xanthan keeps the texture smooth.
I warmed a portion of the jam and drizzled it over the cooled cake. If you choose chia, stir them in after the fruit has cooked so they hydrate rather than cook down.
a bit about the strawberry rhubarb coffee cake topping
The crumb topping is tender rather than crunchy. A cinnamon-scented crumble adds a complementary flavor and a pleasant contrast in texture. Don’t skip the cinnamon—the warm spice enhances both the rhubarb and strawberry flavors.
what sweeteners work best
I used two sweeteners in this recipe for specific reasons. Allulose is my favorite for jams, refrigerated desserts, and frozen treats because it does not crystallize when chilled and behaves very similarly to sugar in texture and taste.
If allulose doesn’t agree with you, swap in a bulky granular sweetener such as Swerve, xylitol, or erythritol. Note that xylitol is toxic to dogs and cats, so avoid it if you have pets. I used a monk fruit/erythritol blend for the cake layers due to limited access to allulose where I live.
If you prefer, adjust sweeteners to suit your taste and tolerance. For jam, avoid powdered stevia as it can produce an off texture in my experience.
strawberry rhubarb coffee cake storage and serving suggestions
I enjoy this cake chilled from the fridge. My husband prefers it warmed briefly in the microwave with a spoonful of whipped cream. Both are excellent. Store the cake covered at room temperature for up to three days, or refrigerated for up to five days.
This cake doesn’t freeze well, so plan to enjoy it within a few days for best texture and flavor.
More recipes you might find intriguing …
If you like handheld snack cakes, try bakery-style chocolate chip muffins or the intensely chocolate Triple Chocolate Muffins. There’s also a versatile sugar-free birthday cake recipe that works well as a base for many white-cake applications.
Low Carb Strawberry Rhubarb Coffee Cake (Gluten-Free & Keto Friendly)
12
15 minutes
30 minutes
1 hour
1 hour 45 minutes
A low carb and gluten free strawberry rhubarb coffee cake. This coffee cake is crumbly and moist, and goes great with a dollop of fresh whipped cream.
Ingredients
Jam
- 1 1/4 cup fresh strawberries (chopped)
- 1 1/4 cup rhubarb (chopped)
- 3/4 cup allulose
- 1/2 tsp xanthan gum
- 1/4 cup water
Cake batter
- 2/3 cup erythritol (powdered)
- 3 large eggs
- 1/4 cup almond milk
- 1 tsp apple cider vinegar
- 1 1/2 cups almond flour
- 1/4 cup coconut flour
- 1 1/2 tsp baking powder
- 1/2 tsp xanthan gum
- 1 tsp vanilla
- 2/3 cup butter
Crumble Topping
- 1 cup almond flour
- 1 tsp baking powder
- 1 tsp cinnamon
- 4 Tbsp melted butter
Instructions
Jam Filling
1. Chop strawberries and rhubarb, then place them in a small saucepan with 3/4 cup allulose, 1/4 tsp xanthan gum, and 1/4 cup water.
2. Cook gently over medium heat until the water reduces and the mixture thickens. Avoid high heat and rapid boiling.
3. Remove from heat and let cool.
Crumble Topping
1. Melt the butter.
2. In a small bowl, combine almond flour, cinnamon, and baking powder.
3. Add melted butter and mix until the mixture resembles coarse crumbs. Set aside.
Cake Batter
1. Preheat the oven to 350°F and prepare a 9×9-inch square pan lined with overlapping parchment strips.
2. Whisk the eggs on high speed for 2 minutes.
3. Melt the butter until soft but not hot. Combine melted butter, almond milk, vanilla, and apple cider vinegar with the whisked eggs.
4. In a separate bowl, sift together almond flour, coconut flour, baking powder, xanthan gum, salt, and powdered erythritol.
5. Gently fold the wet mixture into the dry ingredients until just combined. Do not overmix.
Assembly
1. Spread half the batter evenly in the prepared pan. Use the back of a spoon lightly coated with melted butter to help spread.
2. Spread 2/3 of the cooled jam over the batter.
3. Dollop the remaining batter over the jam and gently spread into an even layer. A little jam peeking through is fine.
4. Sprinkle the crumble topping evenly over the cake.
5. Loosely tent the pan with foil and bake for 20 minutes.
6. Remove the foil and bake another 10 minutes, or until a toothpick inserted in the center comes out clean.
7. Let the cake cool completely in the pan before lifting it out using the parchment.
8. Warm any leftover jam and drizzle it over the cooled cake. A smear of softened cream cheese can be added for extra richness, if desired.
Nutrition Information:
Yield: 12
Serving Size: 1
Amount Per Serving:
Calories: 308
Total Fat: 28g
Saturated Fat: 11g
Trans Fat: 1g
Unsaturated Fat: 15g
Cholesterol: 84mg
Sodium: 242mg
Carbohydrates: 9g
Fiber: 4g
Sugar: 3g
Protein: 7g
