Rhubarb Custard Bars

With their buttery crust, rich-and-tart filling and cream cheese topping, rhubarb custard bars are a potluck hero. You can bake them in one pan and cut them to whatever size you desire, or make two smaller desserts to share. And since the recipe works just as well with fresh or frozen rhubarb, you can make 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 when consumed 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 fruity, sour and perfect for turning into desserts and other rhubarb recipes.

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

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 of it instead of 1 cup of 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 cream and whipping cream are almost the same, but whipping cream may have a slightly lower fat content. Don’t have either? You can make a heavy cream substitute by mixing milk and butter. You can use half-and-half or whole milk with nice results.
• Eggs: If you can find farm-fresh eggs, they are the best eggs to buy, but large Grade A eggs from the store fit the bill.
• Rhubarb: Look for firm, smooth rhubarb stalks. Even though huge stalks look impressive, thinner stalks are often more tender. You’ll want to trim off the bottoms before using them. Red and green rhubarb taste the same, although the red variant makes for a nice visual.
• 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 the crust mixture into a greased 13×9-inch baking pan. Bake the crust for 10 minutes. Let it cool briefly before filling it.

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. 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 the bars until the custard sets, 40 to 45 minutes. Let the custard cool.

Step 3: Make the topping

For the topping, beat the cream cheese, sugar and vanilla until they’re smooth, then fold in the whipped cream. Spread the cream cheese mixture over the cooled custard bars. Cover and chill the bars. Once they’ve cooled, cut the bars and store them 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.

Recipe Variations

• Diversify your fruits: Rhubarb is terrific when combined with other fruits, especially its most famous partner, strawberry (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. Fruits 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 to this dessert. Elderflower liqueur like St-Germain would work beautifully, too.
• Add floral flair: A scant teaspoon of rose water adds an 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 them.
• 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 foods? You can use extra rhubarb (up to the 6-1/2 cups mentioned above) without increasing the sugar, or keep the rhubarb quantity the same while decreasing 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.

Can you freeze rhubarb bars?

Yes, you can 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.

Rhubarb Bars Tips

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 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 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).

Can you use Cool Whip instead of homemade whipped cream?

Yes, you can use Cool Whip instead of homemade whipped cream for the topping. Just make sure to thaw the Cool Whip in the fridge for four hours first so it folds into the whipped cream cheese easily. You’ll only need 1 cup, so save the rest for fruit dip and other Cool Whip recipes, for no-bake cheesecake tartlettes, or to use as a topping for homemade fruit pie.

Watch How to Make Rhubarb Custard Bars

ⓘ

back to content