Creating Blackberry Lemon Bars can be an enjoyable process if you follow these clear and concise steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Prepare a 9-inch square baking dish by greasing it lightly or lining it with parchment paper.
2. Make the Crust: In a medium bowl, combine the flour, granulated sugar, and salt. Add the softened butter and mix until crumbly. Press the mixture evenly into the bottom of the prepared baking dish.
3. Bake the Crust: Place the crust in the preheated oven and bake for 15-20 minutes, or until lightly golden.
4. Prepare the Filling: While the crust bakes, whisk together the eggs and granulated sugar in a separate bowl until well combined. Add the lemon juice, lemon zest, and baking powder, mixing until smooth.
5. Add Blackberries: Gently fold the blackberries into the filling mixture. Avoid over-mixing to keep the berries intact.
6. Pour Filling: Once the crust is done baking, pour the lemon-blackberry filling over it, spreading it evenly.
7. Bake the Bars: Return the dish to the oven and bake for another 20-25 minutes, or until the filling is set and lightly golden on top.
8. Cool the Bars: Once baked, remove the bars from the oven and let them cool in the baking dish. It’s best to let them cool for at least an hour at room temperature before slicing.
9. Dust with Powdered Sugar: Just before serving, dust the top with powdered sugar for a beautiful finish.

These steps will lead you to a plate of irresistible Blackberry Lemon Bars that everyone will adore!