Preheat oven to 350°F and line a 9x13 pan with parchment paper.
In a medium bowl whisk all-purpose flour, almond flour, granulated sugar and salt.
Combine melted butter with dry ingredients. Spread dough evenly across bottom of the prepared 9x13 pan. Bake for 20 minutes or until lightly browned.
After the crust is baked reduce oven heat to 325°F.
Blood Orange Curd Filling
While crust is baking make the filling: Add 1/2 of the sugar to a small pot and set aside.
In a medium bowl whisk the remaining sugar and the egg yolks until well combined. Set aside.
To the small pot add the blood orange juice and lemon juice then whisk to combine with the sugar. Bring to a boil over medium low heat.
Once boiling remove from heat and temper eggs by very slowly pouring 3/4 of the boiling juice into the eggs while constantly and vigorously whisking.
Add the egg mixture to the pot and whisk constantly over low heat until thickened. The curd will be done when it coats the back of a spoon. Remove from heat and mix in cubed butter until fully incorporated.
Strain curd then evenly spread over the baked shortbread crust. Bake at 325°F for 25 minutes. Cool on a wire rack then place in the fridge for at least 2 hours. If desired dust with confectioners' sugar before serving.
Notes
Weigh your ingredients using a kitchen scale! Measuring ingredients by volume is not accurate.
Butter: I recommend using unsalted butter. You can use salted butter for the crust, just be sure to omit the 1/4 tsp salt.
Store blood orange bars in an airtight container for up to one week in the fridge.
The almond flour can be substituted with all-purpose flour.
Nutrition: the provided nutritional information is an estimate per serving. Please read my Nutrition Disclaimer for more information.