I love blueberries and especially their health benefits. This blueberry streusel bar was just so darn good! Of course I used fresh blueberries because I do not care for the messy frozen version – the blueberry juice is dangerous when thawed! The blueberries do need to be at room temperature so plan ahead since using cold blueberries may impact the even baking of the bars. Overall bake time is about 50-minutes. Cooling time before serving is about an hour. So planning ahead is important. For best flavor serve them warm!
We really enjoyed these blueberry streusel bars. If I were to make them again I would reduce the cake ingredients as the crust was a bit thick for me. Also I would reduce the reserved cake mixture used as the topping – maybe reduced by a half. I did think it took the focus away from the blueberry lemon-cream filling however not everyone agreed with me. As always it is your own preference. Do you want the emphasis on the cake with the filling as an accent or the focus on the filling?
If you would like more of the filling then reduce the cake ingredients and if you like a cake type streusel with less emphasis on the blueberries then make it as is! We did find that the excess topping will shake off the bars and can be a bit messy! If you can, heat it in the microwave before serving to bring out the flavors. A scoop of vanilla ice cream would go nicely with a warm blueberry streusel bar!
This recipe was inspired from Fine Cooking Appetizers: 200 Recipes for Small Bites with Big Flavor. This appetizer book has a lot of wonderful recipes!
Cake Ingredients:
3 cups flour
1-1/2 cups old-fashioned rolled oats (not quick oats)
1-1/3 cups packed light brown sugar
1 tsp. salt
1 tsp. baking powder
1 cup unsalted butter, softened
1 large egg white
Lemon-Cream Filling Ingredients:
14-oz can sweetened condensed milk
1/2-cup fresh lemon juice
1 large egg yolk
2 tsp. grated lemon zest
Blueberries Ingredients:
2-1/2 cups room-temperature blueberries, washed and drained on paper towels
Cake Directions:
Position a rack in the center of the oven and heat the oven to 350°F. Line a 9×13-inch metal baking pan with foil, leaving a 1-inch overhang on the ends. Spray the bottom and sides of the foil with a non-stick spray.
In a large bowl combine the dry ingredients (except for the egg and butter). Blend the room-temperature butter completely into the flour mixture (a pastry blender or two knives can help with this process). Transfer 2 cups of crumb mixture to another bowl and reserve for the topping. Blend the egg white into the remaining crumbs and then press the mixture into the bottom of the pan to form a crust. I like to use the bottom of a measuring cup to press down the crumbs to even it out. Bake the crust until it starts to form a dry top, 10 to 12 minutes.
Lemon-Cream Filling Directions:
Meanwhile, in a medium bowl, whisk the condensed milk, lemon juice, lemon zest, and egg yolk. Let this mixture stand for 5 minutes; it will begin to thicken.
Assembling the Blueberry Bars Directions:
Take the cake out of the oven once the crust is formed. Sprinkle the blueberries evenly over the hot crust and then drop spoonful of the lemon mixture over the blueberries. Gently distribute with a spatula, but be careful to not crush the blueberries. Do not worry about it being perfect. Return the cake to the oven and bake until the lemon mixture just begins to form a shiny skin, 7 to 8 minutes.
Topping the Blueberry Bars Directions:
Take the cake out of the oven and sprinkle the reserved topping over the lemon-blueberry layer, pressing the streusel between your fingers into small lumps as you sprinkle. Return the cake and bake until the filling is bubbling at the edges and the topping is brown, 25 to 30 minutes.
Let the blueberry bars cool in the pan on a rack until just warm, about an hour. Carefully lift them out of the pan using the foil overhang and transfer to a wire rack to cool completely. Remove the foil and cut into 24 bars when cool. The bars may be stored at room temperature for a few hours but otherwise should be kept in the refrigerator.
