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Plate of oatmeal cookie bars.

Strawberry Rhubarb Oatmeal Cookie Bars

Sweet and buttery strawberry oatmeal cookie bars are filled with juicy, ripe fruit, sweet brown sugar and golden oats all baked to a chewy perfection. Lemon thyme glaze makes these jammy, fruit-filled squares a modern treat for kids and grown-ups alike.
Course Dessert
Cuisine American
Keyword fruit bar, granola bar, oat bar
Prep Time 15 minutes
Cook Time 40 minutes
Total Time 55 minutes
Servings 16
Calories 255kcal
Author Debs


Oat Mixture

  • 2 1/2 cups rolled oats
  • 1 1/4 cups all-purpose plain flour
  • 1 cup light brown sugar
  • 1 Tbsp lemon zest
  • 1/2 tsp sea salt
  • 1 cup cold butter cubed

Strawberry Rhubarb Filling

  • 2 cups chopped strawberries
  • 1 cup chopped rhubarb
  • 1/2 granulated caster sugar
  • 1/3 cup lemon juice approx. 1 lemon
  • 2 Tbsp cornstarch

For the Glaze

  • 3 Tbsp icing sugar
  • 1-2 Tbsp water
  • 1 sprig thyme leaves


  • Line an 8-9 inch square metal pan with baking parchment. Set aside.

Strawberry Rhubarb Filling

  • In a saucepan, bring the fruit, sugar and lemon juice to the boil; reduce heat and simmer until tender, about 10 minutes. Whisk the cornstarch with 2 tablespoons cold water; whisk into strawberries and rhubarb and boil, stirring until thickened, about 1 minute. Place plastic wrap directly on the surface, so a skin doesn’t form, and refrigerate until cold, about 1 hour.
  • In the bowl of a food processor, add the oats, flour, brown sugar, lemon zest, salt and butter. Blend on the pulse setting until a breadcrumb texture is achieved, about 1 minute. Press half of the mixture into the prepared pan; being sure that you’ve pressed firmly. Spread with the strawberry rhubarb filling. Sprinkle with the remaining mixture, pressing lightly.
  • Preheat the oven to 350f (180c) and bake the bars until golden brown, about 40 minutes. Let cool in the pan on a rack. Cut into squares.

For the Glaze

  • Mix the icing sugar with the water and add the lemon thyme leaves. Drizzle the glaze over bars
  • Optional: Garnish with flower petals and more herb leaves. 


Cook’s notes 1: You need to bring the filling mixture to a boil once you’ve added the cornstarch to achieve maximum thickening potential and cookout the taste to the starch.
Cook’s notes 2: These bars can be made ahead and frozen before slicing. Simple bake and once cool, wrap and store in a double layer of foil before freezing. To defrost, just leave at room temperature for about 30 minutes. OR Cut and freeze individually to have a grab and go snack.