Description
Sometimes the best recipes come from happy accidents in the kitchen, and consequently, Lemon Oatmeal Crumble Bars are proof of that beautiful truth. Furthermore, these delightful treats combine the bright, refreshing zing of fresh lemon with the comforting, wholesome texture of oats in a way that’s simply irresistible. Whether you’re hosting a book club meeting, bringing treats to a church potluck, or simply want to brighten up an ordinary Tuesday afternoon, these bars deliver sunshine in every bite.
Ingredients
Essential Ingredients for Outstanding Results
For the Oat Crumble Layers:
- 2 cups old-fashioned rolled oats
- 1½ cups all-purpose flour
- 1 cup packed light brown sugar
- ½ cup granulated sugar
- 1 teaspoon baking powder
- ½ teaspoon salt
- 1 teaspoon vanilla extract
Lemon Filling:
- 4 large eggs
- 1½ cups granulated sugar
- ¼ cup all-purpose flour
- ½ cup fresh lemon juice (about 3–4 large lemons)
- 2 tablespoons lemon zest
- ¼ teaspoon salt
- 3 tablespoons unsalted butter, melted
- ¼ cup heavy cream
Finishing:
- Powdered sugar for dusting
- Additional lemon zest for garnish
Instructions
First and foremost, preheat your oven to 350°F and line a 9×13-inch baking pan with parchment paper, leaving some overhang for easy removal. Importantly, this step is crucial – trust me, you don’t want to struggle to get these beautiful bars out of the pan intact. Next, lightly grease the parchment paper with butter or cooking spray.
In a large mixing bowl, combine oats, flour, brown sugar, granulated sugar, baking powder, and salt. Then, mix these dry ingredients thoroughly with a fork or whisk. Notably, the key to great crumble is ensuring all dry ingredients are evenly distributed before adding the wet ingredients.
After that, add the vanilla extract and cold, cubed butter. Using a pastry cutter or your clean hands, work the butter into the dry ingredients until the mixture resembles coarse crumbs with some larger, pea-sized pieces of butter. As a result, this technique creates those delightful crispy-tender textures we love in a good crumble.
First, reserve about 1½ cups of the oat mixture for the topping. Then, press the remaining crumble mixture firmly and evenly into the bottom of your prepared pan. For best results, use the bottom of a measuring cup or your hands to create a compact, even layer. Indeed, this base needs to be sturdy enough to support the lemon filling without becoming soggy.
Subsequently, bake the crust for 15-18 minutes, until it’s lightly golden around the edges and set in the center. Most importantly, don’t skip this pre-baking step – it ensures your bottom crust stays crisp and doesn’t get soggy from the lemon filling.
Meanwhile, while the crust bakes, prepare your lemon filling. In a large bowl, whisk the eggs until well beaten. Next, gradually add the granulated sugar, whisking constantly until the mixture is smooth and well combined. At this point, the sugar should be completely dissolved.
In a separate small bowl, whisk together the flour and salt. Then, add this to the egg mixture, whisking until smooth. Finally, slowly add the fresh lemon juice, lemon zest, melted butter, and heavy cream, whisking constantly to prevent curdling. As a result, the filling should be smooth and pourable.
Pour the lemon filling over the hot, pre-baked crust. Working quickly, sprinkle the reserved oat crumble mixture evenly over the lemon filling. However, don’t worry about covering every inch – those peek-through spots of bright yellow lemon filling are beautiful and add visual appeal.
Return to the oven and bake for 22-25 minutes, until the top is golden brown and the filling is set but still has a slight jiggle in the center. Additionally, the bars will continue to set as they cool.