Print

Lemon Oatmeal Crumble Bars Recipe

4.4 from 28 reviews

These Lemon Oatmeal Crumble Bars combine a buttery, crunchy oatmeal crust and crumble topping with a smooth and tangy lemon filling, making a perfect dessert for any occasion. Their balance of sweet and tart flavors paired with a hearty oat texture make them a delightful treat that’s easy to prepare and sure to impress.

Ingredients

Scale

For the Crust & Topping:

  • 7 tablespoons (99g) unsalted butter, softened to room temperature
  • 3/4 cup (150g) light or dark brown sugar, packed
  • 1 teaspoon vanilla extract
  • 1 cup (125g) all-purpose flour (spooned & leveled)
  • 1 teaspoon baking powder
  • 1/4 teaspoon salt
  • 1 cup (85g) old-fashioned oats or quick oats (not instant)

For the Lemon Filling:

  • 1 can (14 ounces) full-fat sweetened condensed milk
  • 6 tablespoons (90ml) lemon juice (from about 2 lemons)
  • 1 tablespoon lemon zest (from about 1 lemon)

Instructions

  1. Prepare the oven and pan: Preheat your oven to 350°F (177°C). Line an 8-inch square baking pan with parchment paper, which will make removing the bars easier after baking.
  2. Make the crust and topping: Using a handheld mixer or stand mixer with a paddle attachment, beat the softened butter and brown sugar on medium-high speed until fully combined, about 1 minute. Scrape down the bowl sides, add vanilla extract, and beat again for 30 seconds. Add the flour, baking powder, salt, and oats, then mix on medium speed until a crumbly, dry mixture forms, totaling about 3 to 3.5 cups.
  3. Form the crust: Press slightly more than half of the crumble mixture evenly into the bottom of the prepared pan to create the crust layer. Bake this crust for 12 minutes, then remove it from the oven.
  4. Make the lemon filling: In a medium bowl, whisk together the full-fat sweetened condensed milk, fresh lemon juice, and lemon zest until smooth and thick.
  5. Assemble the bars: Pour the lemon filling over the warm, pre-baked crust and spread it evenly. Then sprinkle the remaining crumble mixture over the lemon filling as a topping.
  6. Bake: Return the pan to the oven and bake for an additional 22 to 25 minutes, or until the edges turn lightly golden and the center is set. Avoid over-baking to keep the filling creamy.
  7. Cool and cut: Once baked, remove the bars from the oven and cool the pan completely on a wire rack. Use the parchment paper to lift the bars out, then cut into 16 squares.
  8. Storage: Store the leftover bars at room temperature for up to 2 days or refrigerate for up to 1 week to maintain freshness.
  9. Freezing Instructions: To freeze, layer cut bars in a freezer-safe container with parchment paper between layers. They freeze well for up to 3 months. Thaw overnight in the refrigerator and bring to room temperature before serving.

Notes

  • Use full-fat sweetened condensed milk, not evaporated or fat-free versions, to ensure the filling sets properly.
  • You can double this recipe and bake in a 9×13-inch pan. Increase crust pre-bake time to 18 minutes and bake the filled bars for 35 minutes or until set.
  • Press slightly more crumble mixture for the crust than for the topping to balance texture.
  • Do not over-bake to prevent a dry or cracked filling.
  • Allow bars to cool completely for clean slicing and best texture.

Keywords: Lemon Oatmeal Crumble Bars, lemon bars, oatmeal dessert, crumble topping, easy dessert, lemon filling, sweetened condensed milk dessert