Keto Rhubarb Custard Bar Recipe

This Easy Keto Rhubarb Custard Bar recipe is so delicious!  By combining a crispy gluten-free shortbread crust with a creamy sugar-free rhubarb custard layer and then topping it off with a refreshing light low carb whipped cream frosting, these Keto Rhubard Custard Bars are the perfect treat to bring to your next summer gathering.

It is time for my confession of the month...

The thing is, I actually have never had rhubarb.

Actually, that's not exactly true.  I do remember playing in a vacant piece of land with my sisters and coming across what we believed was "rhubarb".

Being the youngest of the three and always wanting to please my sisters, they told me to try and so of course, I did.

And it was DISGUSTING!  Bitter as heck, I spit it out as fast as possible.

Hence, my lack of ever trying rhubarb again!

Until today!

These bars were ranked one of the top recipes on Taste of Home so I decided to modify them slightly to make them not only gluten-free but also sugar-free.

And I am glad I did!

Just like my One-Bowl Lemon Lime Bars or my Chocolate Covered Shortbread Bars, these low carb Rhubarb Custard Bars are simple to make, require very few ingredients as well as time, and were a hit with Mr. Grumbles!

What is rhubarb?

According to the Huff Post, Rhubarb is technically a vegetable but is legally considered a fruit. In 1947 a New York court declared rhubarb a fruit because it's most often cooked as one in the United States.

Rhubarb is sold at farmers' markets and grocery stores by the stalk, like celery. It's harvested in the spring, with a short season that spans from April to June. Rhubarb stalks are famous for their bright pink colour, as pictured above, but they can also be light pink and even pale green. The colour is not an indication of ripeness or sweetness like it is with other fruits. The stalks are the only edible part of the plant; in fact, the leaves of rhubarb are poisonous.

What are the health benefits of rhubarb?

• good source of magnesium
• very good source of dietary fibre,
• a high source of vitamin C, vitamin K, calcium, potassium and manganese.
• low in saturated fat and sodium
• very low in cholesterol
• high in antioxidants

What is the nutritional profile of rhubarb?

1 cup of raw rhubarb has:

• 26 calories
• 0.2 grams of fat
• 5.5 grams of carbs
• 2.2 grams of fibre
• 1.3 grams of sugar
• 3.3 grams net carbs
• 1.1 grams of protein

What ingredients do you need to make this Keto Rhubarb Custard Bar recipe?

For the Shortbread Crust:

• almond flour
• coconut flour
• sweetener (I used Lakanto Classic in the shortbread and rhubarb layer and Allulose in the whipped topping)
• cardamom (OPTIONAL)
• salt
• cold butter, diced, unsalted

For the Rhubarb Filling:

• sweetener
• almond flour
• heavy whipping cream 
• eggs
• diced fresh rhubarb 

For the Topping:

• cream cheese softened
• powdered sweetener
• vanilla
• heavy whipping cream

How do you make these Keto Rhubarb Custard bars?

• Prepare the crust and bake it in the oven until it begins to brown
• As the crust bakes, prepare the rhubarb filling
• Once the crust has been slightly baked, spread rhubarb filling over the crust and return it to the oven
• Once the rhubarb bars have been baked, allow them to cool completely

• Spread the cream cheese whipped topping over the bars
• ENJOY!

Tips, Tricks and Substitutions for this Keto Rhubarb Custard Bar Recipe:

• If you don't have cardamom for the crust, feel free to eliminate it completely
• To lighten these bars, simply use half and half instead of heavy cream in the rhubarb filling
• Feel free to swap out Cool Whip for the topping
• Do NOT over whip your cream as it will lose its shape and return to a liquid state
• If you can't find fresh rhubarb, feel free to use frozen rhubarb
• If you are using frozen rhubarb, make sure to thaw and drain it well before using
• Feel free to use regular sugar instead of sweetener in an equal 1:1 ratio
• Feel free to use regular AP flour but add additional flour to get the desired consistency

If you like this Keto Rhubarb Custard Bar Recipe, you may also enjoy:

• Easy Keto Strawberry Shortbread Bars
• Lemon Curd Custard Bars
• Maple Pecan Pie Bars (Gluten-Free, Keto)
• Pumpkin Chiffon Cheesecake Bars (Gluten-Free, Keto, Easy)

Keto Rhubarb Custard Bar Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

5 from 2 reviews

Print Recipe

Pin Recipe

A crispy shortbread crust with a creamy rhubarb custard layer and then topping it off with a refreshing light whipped cream frosting, this keto and gluten-free recipe is perfect for your next summer gathering

• Total Time: 1 hours 5 minutes
• Yield: 16 bars 1x

Ingredients

Units USM Scale 1x2x3x

For the Shortbread Crust:

• 1 cup almond flour
• ¼ cup coconut flour
• 2-3 tablespoon sweetener
• ½ tsp cardamom (OPTIONAL)
• ¼ tsp salt
• ½ cup cold butter, diced, unsalted

For the Rhubarb Filling:

• 1 cup sweetener (you could slightly less if you like your bars a little more tart)
• ¼ cup almond flour
• ½ cup heavy whipping cream (or half and half or whole milk)
• 2 large eggs, room temperature, beaten
• 4-5 cups (about 500 g or 1 lb) diced fresh rhubarb (or frozen, thawed and drained)

For the Topping:

• 4 oz cream cheese, softened
• ¼ cup powdered sweetener
• ½ tsp vanilla
• ½ cup heavy whipping cream, whipped

Cook Mode Prevent your screen from going dark

Instructions

1. In a bowl, combine the almond flour, coconut flour and sugar.  Take the diced butter and mix until the mixture resembles coarse crumbs.  Press into a greased 8 x 8 (or 9 x 9) baking pan.
2. Bake at 350 degrees for 10 minutes
3. While the crust bakes, combine the sweetener and flour in a bowl.  Whisk in the cream and eggs.  Stir in the rhubarb.  Once the crust is done, pour the mixture over the crust and return it to the oven for 40-45 minutes or until the custard has set.  Allow cooling.
4. Whip the heavy cream until tripled in size and set aside
5. For the topping, beat the cream cheese, sweetener and vanilla until smooth.  Fold in the whipped cream.  Spread the topping over the bars.  Cover the bars and place them in the fridge to set.  Once bars have set, cut them into the desired size.
6. Store bars in the fridge.

Notes

• Feel free to use half and half in the rhubarb layer instead of heavy cream if you want a lighter version

• Author: Cat
• Prep Time: 10 minutes
• Cook Time: 55 minutes
• Category: Dessert
• Method: Baking
• Cuisine: Keto, Low Carb, Gluten Free

Nutrition

• Serving Size: 1 bar
• Calories: 183
• Sugar: 1.4 g
• Fat: 16.8 g
• Carbohydrates: 5.6 g
• Fiber: 2.1 g
• Protein: 3.9 g