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Lemon Oatmeal Crumble Bars Recipe

Lemon Oatmeal Crumble Bars Recipe

Bake golden Lemon Oatmeal Crumble Bars Recipe with tangy lemon filling and crumbly oat topping. Sweet, citrusy, and melt-in-your-mouth delicious.
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Prep Time 15 minutes
Cook Time 35 minutes
Total Time 50 minutes
Course Dessert
Cuisine American
Servings 9 to 12 bars
Calories 220 kcal

Equipment

  • Mixing bowls
  • Whisk or fork
  • Measuring Cups and Spoons
  • 8x8-inch baking pan
  • Parchment paper
  • Zester or fine grater (for lemon zest)
  • Microplane or fine sieve (optional, for a smooth filling)
  • Oven
  • Cooling rack

Ingredients
  

For the Crust and Crumble:

  • 1 1/2 cups old-fashioned rolled oats
  • 1 cup all-purpose flour
  • 1/2 cup light brown sugar packed
  • 1/4 teaspoon salt
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon cinnamon optional
  • 3/4 cup unsalted butter melted

For the Lemon Filling:

  • 2 large eggs
  • 3/4 cup granulated sugar
  • 1/4 cup all-purpose flour
  • 2 tablespoons lemon zest from about 2 lemons
  • 1/3 cup fresh lemon juice about 2 lemons
  • 1/2 teaspoon vanilla extract optional

Optional toppings:

  • Powdered sugar for dusting
  • Extra lemon zest for garnish

Instructions
 

Step 1: Preheat Oven

  • Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, leaving some overhang to easily lift the bars later.

Step 2: Make the Crust and Crumble

  • In a medium bowl, combine rolled oats, flour, brown sugar, salt, baking soda, and cinnamon if using. Pour in melted butter and stir until crumbly. Reserve about 1/3 of the mixture for the crumble topping.
  • Press the remaining oat mixture firmly into the bottom of the prepared pan to form the crust. Bake for 10–12 minutes, or until lightly golden. Remove from oven and set aside.

Step 3: Prepare the Lemon Filling

  • In a separate bowl, whisk together the eggs and granulated sugar until smooth. Add flour, lemon zest, lemon juice, and vanilla extract if using. Mix until fully combined and pourable.

Step 4: Assemble the Bars

  • Pour the lemon filling over the pre-baked crust, spreading evenly. Sprinkle the reserved oat crumble over the top, covering the filling gently.

Step 5: Bake

  • Return the pan to the oven and bake for 20–25 minutes, or until the filling is set and the crumble topping is golden brown. Keep an eye on the topping to ensure it doesn’t over-brown.

Step 6: Cool and Serve

  • Allow the bars to cool completely in the pan on a wire rack. Once cooled, lift them out using the parchment overhang and cut into squares or rectangles. Dust with powdered sugar and sprinkle extra lemon zest if desired.

Notes

  • Use fresh lemons for juice and zest; bottled juice won’t give the same brightness.
  • Make sure the butter for the crust is fully melted to bind the oats.
  • Press the crust firmly to avoid it crumbling when cutting.
  • Don’t overbake the lemon layer; it should be set but slightly soft in the center.
  • Cool completely before slicing for clean edges.
  • For extra flavor, you can add a teaspoon of finely grated lemon zest to the crumble topping.
  • Store in an airtight container at room temperature or refrigerate for a firmer texture.
Keyword Lemon Oatmeal Crumble Bars Recipe