Rhubarb Custard Bars (2024)

A layered dessert with a buttery crust, a rhubarb-filled custard and a sweet and tangy cream cheese topping, rhubarb bars are a potluck hero and truly one of the best rhubarb recipes. You can bake them in one pan and cut them into whatever size you desire, or make two smaller desserts to share. Using fresh or frozen rhubarb means making these delicious bars anytime.

In the wild, rhubarb is a fascinating plant. Its massive leaves, which look like something you’d find in a tropical rainforest, are harmful because of their high oxalic acid content (the stuff that makes your teeth feel weird when you eat spinach). But the thick, juicy stalks beneath those leaves are deliciously fruity, sour and perfect for turning into desserts.

Because rhubarb is quite tangy, it is a wonderful counterpoint to rich dairy products. These delicious, fruity rhubarb bars showcase that exact quality.

Ingredients for Rhubarb Custard Bars

• Flour: This recipe calls for standard all-purpose flour. You can easily turn these into a gluten-free recipe by swapping in something like Bob’s Red Mill 1-to-1 Baking Flour.
• Sugar: You’ll use granulated sugar in the crust, the filling and the topping. If you like the taste of maple syrup, you could use 3/4 cup syrup instead of 1 cup sugar in the filling.
• Butter: When making a crust, it’s important to keep the butter very cold as you use it. One great strategy is to cut the butter into chunks and pop them in the freezer for a few minutes before blending them into the flour.
• Cream: Heavy and whipping cream are almost the same, but a carton labeled “whipping cream” may have a slightly lower fat content. Don’t have either? Here’s some info on heavy cream substitutions. You can use half-and-half or whole milk with nice results.
• Eggs: If you can get farm-fresh eggs, they are the best eggs to buy, but store-bought large grade A eggs fit the bill.
• Rhubarb: Look for firm, smooth stems of rhubarb. Even though huge stalks look impressive, thinner stalks are often more tender. You’ll want to trim off the bottoms of the stalks before using them. Also, red and green rhubarb taste the same, although the red variant makes for nice visuals.
• Cream cheese: Cream cheese adds a bit of tang to the topping. Here are some of the best cream cheeses for any recipe.
• Vanilla extract: It’s worth investing in the best vanilla extract for baking (my go-to is Neilson-Massey). Make sure you choose a vanilla labeled “real” or “pure.”

Directions

Step 1: Make the crust

Preheat the oven to 350°F. In a bowl, combine the flour and sugar. Cut in very cold cubes of butter until the mixture resembles coarse crumbs. Press into a greased 13×9-inch baking pan. Bake for 10 minutes. Let cool briefly before filling.

Editor’s Tip: Cut the butter into the flour using a pastry blender or two knives. Or use a food processor. Just use a delicate finger on the pulse button and stop when the mixture looks like crumbs. PS: If you’re cooking for a smaller crowd, you can halve this recipe and bake it in an 8- or 9-inch square pan.

Step 2: Make the filling

While the crust is baking, combine the sugar and flour in a bowl. Whisk in the cream and eggs until the mixture is uniform, and stir in the rhubarb. Pour the mixture over the crust, and bake until the custard sets, 40 to 45 minutes. Let cool.

Step 3: Make the topping

For the topping, beat the cream cheese, sugar and vanilla until smooth, then fold in the whipped cream. Spread the cream cheese mixture over the cooled custard bars. Cover and chill. When cool, cut into bars and store in the fridge.

Editor’s Tip: When you fold ingredients together, use a gentle sweeping motion that starts at the bottom of the bowl and swoops up. Anything more aggressive, and you’ll deflate the fluffy whipped cream.

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Recipe Variations

• Diversify your fruits: Rhubarb is terrific when combined with other fruits, especially its most famous partner, strawberries (case in point: strawberry-rhubarb pie). You can increase the fruit in this recipe to 6-1/2 cups and decide how much of that should be rhubarb and how much should be another fruit. Ingredients that pair exceptionally well with rhubarb include apples, blackberries, oranges, plums and raspberries.
• Layer in liquor: A bit of brandy, Grand Marnier, port, rum or sherry, in addition to or in place of the vanilla, would add a nice element for this dessert. Some elderflower liqueur, such as St-Germain, would work beautifully, too.
• Add floral flair: A scant 1 teaspoon rose water adds a delicious, otherworldly flavor to these rhubarb bars. Orange blossom water would be good, too. For extra style, sprinkle the top of the bars with fresh or dried edible flowers after frosting.
• Try some spice: Add a hint of vanilla with a smidgen of vanilla bean paste. Spices, particularly cinnamon, ginger or nutmeg, would also enhance the dessert.
• Make it more tart or sweet: Do you like tart things? You can use extra rhubarb (up to the 6-1/2 cups mentioned above) without increasing the sugar, or you can keep the rhubarb quantity the same but decrease the sugar in the filling to 1-1/2 cups.
• Add nuts: Add toasted, chopped nuts along with the fruit to give the filling a little crunch. Almonds would be a great match, but hazelnuts and pecans would also work.

How to Store Rhubarb Bars

Custard bars need to be snugly wrapped and stored in the fridge. You could refrigerate them in their baking pan or transfer them to a container with a tight-fitting lid. They’ll last up to four days.

Rhubarb Bars Tips

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Do you need to peel rhubarb before you cook it?

When rhubarb is tender, it doesn’t need to be peeled, and if you have the red type, all of the beautiful blushing color is in the skin. However, if the rhubarb is tough (which can happen later in the harvest season), you could peel it. To cut rhubarb for this recipe, cut off the bottoms. If the stalks are particularly unwieldy, lop them into 3- or 4-inch lengths. Then, cut those chunks into long skinny sticks and cut across the sticks to get a nice, fine chop.

How do you freeze rhubarb bars?

Store the rhubarb bars in a single layer in an airtight container. These will keep beautifully in the freezer for up to three months. Here’s how to cut dessert bars for easy storing, freezing and eating.

How do you serve rhubarb bars?

Classic potluck desserts like rhubarb bars are great for gatherings, dinner parties, bake sales and road-trip treats. Cut them into squares, lay them out on a platter or plate, and prepare to wow your guests (and yourself).

Watch how to Make Rhubarb Custard Bars