I have had so many requests for this recipe since posting this photo on Instagram, so I am sharing it with you today with one caveat: I have only tested this recipe once as written. Generally I make all recipes I post here at least twice before sharing so I can ensure it’s repeatable and work out any kinks. But I just released a cookbook and honestly, I’m so tired!
However, I realize that many of you may want to attempt this over Thanksgiving and holidays, so I’m sharing what I did along with some notes. I do plan to retest these again and will update the recipe accordingly if needed.
A few notes:
- I made these bars with a pretty thick base, which I liked. However, I suspect most people would prefer it a little thinner so the recipe amounts below reflect that. If you’re team extra-thick base, multiply all amounts by 1.45.
- I realize having a couple extra egg whites leftover from the filling may be annoying. However, I really liked this ratio of filling to meringue! The filling is bright and tart and stands up well to the sweet topping. I freeze extra egg whites for future meringue / financiers / macarons or macaroons or just add them to a batch of scrambled eggs. If you want to use just 4 eggs total, then multiply all filling ingredients by .67. (Sure, you could make a bigger batch of meringue but honestly I feel it would be overkill. But your bars, your ratios!)
- Did I mention I just released a cookbook? Baked to Order is available now, wherever books are sold! And if you’ve bought the book and are enjoying it, would you consider writing a review on Amazon? Reviews are incredibly valuable and help others find the book more easily. THANK YOU for your support!
Lemon Pie Bars with Strawberry Meringue
For the graham cracker crust:
- 120g graham cracker crumbs
- Pinch of kosher salt
- 12g light brown sugar
- 42-56g unsalted butter (as needed), melted
For the lemon-elderflower filling:
- 250g granulated sugar
- 1/4 tsp kosher salt
- 53g cornstarch
- 6 large egg yolks
- Zest of 3 lemons
- 170g freshly squeezed lemon juice
- 340g water
- 42g elderflower liqueur (such as St. Germain)
For the strawberry swiss meringue:
- 30g freeze-dried strawberries
- 180g granulated sugar
- 120g egg whites
- 1/8 tsp cream of tartar
- Pinch of kosher salt
- Preheat the oven and prepare the pan: Preheat the oven to 350F with a rack in the middle. Line a 9×5 loaf pan with parchment paper leaving 2 to 3 inches (5 to 7.5 cm) of overhang on the long sides for easy removal. Lightly grease the pan and parchment. Secure the edges of the parchment with metal binder clips, if desired, to make assembly easier (they keep the parchment paper from flapping around).
- Make the graham cracker crust: In a small bowl, mix together the graham cracker crumbs, salt, and sugar. Add about 42g (3T) of melted butter and stir to combine. You’re looking for a wet sand consistency — when you squeeze a bit of the mixture in your hand, it should hold together easily but not feel overly greasy. The amount of butter needed can vary depending on the brand of crumbs and how finely ground they are. Add more melted butter as needed, a teaspoon at a time, until you reach the right consistency.
- Transfer the crumb mixture to the prepared pan and use a small glass or measuring cup to press it along the bottom of the pan firmly and evenly. Bake for about 12 minutes, or until fragrant and just set. Transfer to a wire cooling rack.
- Make the lemon-elderflower filling: Set a sieve over a medium heatsafe bowl. In a medium saucepan, whisk together the sugar, salt, and cornstarch until well combined. Add the egg yolks, zest, lemon juice, water, and liqueur and whisk to combine.
- Cook over low heat until steaming, whisking constantly. Raise the heat to medium-low and continue cooking, whisking constantly, until the mixture thickens and starts to bubble. Once the bubbles appear, continue whisking and cooking for two full minutes (set a timer! It’s important to not skimp on the time or the filling will not set properly). Take care as the mixture will sputter and spit a bit.
- Strain the filling into the prepared container to remove the zest, then scrape the filling over the prepared crust. Cool at room temperature until a skin forms over the surface, about 30-45 minutes, then cover with plastic wrap and refrigerate until the filling is cold and fully set, at least 4 or up to 24 hours.
- Make the strawberry meringue and assemble the bars: About an hour before serving, remove the bars from the refrigerator and transfer to a serving plate. Discard the parchment.
- To make the meringue, fill a medium saucepan with 2-3 inches of water and bring to a simmer. While the water is heating up, combine the freeze-dried strawberries and sugar in the bowl of a food processor. Pulse until the strawberries are ground into a fine powder. Transfer the strawberry-sugar to the bowl of a stand mixer and whisk in the egg whites, cream of tartar, and salt.
- Place the bowl on top of the saucepan to create a double-boiler—this heats the egg mixture gently to avoid scrambling the eggs. The base of the bowl should not touch the simmering water.
- Heat the egg white mixture, stirring frequently and scraping the sides and bottom of the bowl with a heatproof spatula, until it reaches 165°F (74C) on an instant-read thermometer. The mixture should be quite thick and the sugar completely dissolved.
- Remove the bowl from the double-boiler and transfer to a stand mixer fitted with the whisk attachment. Whisk on high speed until the meringue has increased in size 3-4x times and holds glossy medium-stiff peaks, about 4-5 minutes. (It will still be a little warm — don’t overbeat or the meringue can get a little gooey and difficult to spread.)
- Immediately scrape the meringue on top of the lemon filling and use a spatula or spoon to spread it over the top. Swoop and swirl as you desire.
- To serve, use a hot, sharp knife to slice (clean the knife with a hot, damp towel between cuts). The bars are best served immediately. Refrigerate any leftovers in an airtight container.