Anna Olson's Lemon Blueberry Bars
Anna Olson's classic recipe features a crisp, buttery base topped with bright, zesty lemon custard and fresh blueberries. Perfectly balanced and easy to slice.
Ingredients
Crust:
- 1½ cups all-purpose flour
- 6 tbsp icing sugar
- 2 tsp finely grated lemon zest
- ½ tsp fine salt
- ½ cup (115 g) unsalted butter cold
Filling:
- 1¼ cups granulated sugar
- ¼ cup all-purpose flour
- 1 tbsp finely grated lemon zest
- ⅔ cup fresh lemon juice
- ⅓ cup sour cream or crème fraîche see note
- 4 large eggs
- ¾ cup (95 g) fresh blueberries
- icing sugar for dusting
Instructions
- Preheat the oven to 350°F (180°C). Lightly grease a 9-inch (23 cm) square pan and line it with parchment paper so the paper comes up the sides.
- Stir the flour, icing sugar, lemon zest and salt together in a mixing bowl. Use a box grater to grate in the cold butter and use a pastry cutter or your fingertips to work the butter into the dry ingredients until you have a fine, sandy mixture. Alternatively, you can pulse the butter into the flour using a food processor. Tip the crust mixture into the pan, and using the back of a spoon, press it into the bottom and up against the sides just a little. Bake the crust for about 20 minutes, until it begins to brown a bit at the edges.
- While the crust bakes, prepare the filling. Whisk the sugar, flour and lemon zest together in a medium bowl. Whisk the lemon juice and sour cream (or crème fraîche) in a small bowl to combine, then add to the sugar, whisking well. Whisk in the eggs until smooth and evenly combined.
- When the crust comes out of the oven, pour the filling over the still-hot crust. (I find that pouring the filling onto the hot crust starts to cook the filling immediately, which helps prevent it from leaking around the edges – a common issue with lemon bars. It also softens the base ever so slightly so that, once cooled, the bars slice without crumbling.)
- Bake the bar for 15 minutes and then sprinkle the blueberries overtop. Continue baking for an additional 10 to 15 minutes, until the filling is set when the pan is gently jiggled. If the filling rises up at the edges, turn down the oven temperature to 325°F (160°C). Cool in the pan on a rack and then chill for at least 4 hours before cutting into bars. (The bars will keep in an airtight container or loosely wrapped in the fridge for up to 4 days.)
Notes
To make your own crème fraîche:
- Stir 1 cup whipping cream and 1 tbsp buttermilk or fresh lemon juice together, place in a glass pitcher or bowl and cover. Set the pitcher into a larger bowl and fill the larger bowl with hot tap water up to the line of the cream. Let sit on the counter for 24 to 36 hours.
- Lift the glass pitcher or bowl out of the water and look to see if there is liquid separated and sitting at the bottom. If not, let the pitcher sit out for another 12 hours (not in a water bath this time). Do not stir. Chill the pitcher for 3 hours, then spoon off the crème fraîche without stirring in the whey. Chill until ready to use. Store in an airtight container in the fridge until the best-before date of the whipping cream.