Luscious Black-Berry Topped "Grapefruit N Lime" Squares

I love Greek Lemon Squares or any citrus squares for that matter. With its crumbly cookie-like crust and jelly-like topping its a perfect little dessert with a tangy note. Awesome with a cup of tea or a nice finish to a perfect meal. Last week I bought half a dozen grapefruits to make some grapefruit squares, an equally refreshing and eye-catching alternative to Lemon Squares.Recipe adapted from this recipe that is our family's favorite summer dessert. I made this for a get together last week and it got two thumbs-up. Lovely dessert with citrus fruits and berries, no?
Please read the "Notes" if planning on trying this at home.This goes to "The Bake-off" event held at The Versatile Kitchen.

Ingredients:
For the Crust:

• Butter - 2 sticks(1 cup), at room temperature
• Light Brown Sugar - 1/2 cup
• King Arthur Unbleached All-Purpose Flour - 2 cups
• A pinch of salt

For the Filling:

• Eggs - 4, at room temperature, whisked
• Grapefruit Juice - 2/3 cup
• Lime Juice - 1 tbsp
• Grapefruit Zest - 1 tbsp
• Lime Zest - 1 tbsp
• All purpose flour - 3 tbsp
• Condensed Milk - 1/4 cup
• Granulated Sugar - 1 1/2 cup
• Red food Coloring - 3 drops (Optional)
• Confectioner's Sugar - for dusting (Optional)
• Black Berries - a handful, for Topping (Optional)

Tool:

• 9 X 13 inch Oven-Proof baking pan

Procedure:

• Combine all the ingredients under "For the Crust" in a food processor and pulse until they resemble a coarse meal.

• Pat the mixture on the bottom of the greased oven-proof baking pan and bake it for 20 minutes at 350 degrees F.

• While the crust is baking, combine the whisked eggs, both the juices, zest, all-purpose flour, condensed milk using a hand mixer or whisk.
• Add the sugar little by little and mix until they dissolve.
• Warm the filling mixture in a sauce pan on low flame(Gas Mark 4 or 5), STIRRING CONSTANTLY using a whisk for 8 minutes. No more no less.
• Switch off stove and add red coloring if using. Mix gently and pour it on the top of the warm crust.
• Bake for 10-15 minutes at 350 degrees F or until a toothpick inserted in the center comes out clean.

• Let it rest for 10-15 minutes and REFRIGERATE for 4-5 hours prior to cutting into squares.
• Top each square with blackberries or dust them with confectioner's sugar just before serving.
• Serve slightly cold. 

Makes ~25 to 30 squares

Note:

• For a "clean cut" of the squares they have to be REALLY cold.
• Use a big butcher's knife rather than pizza roller(like me) to avoid dragging the filling.
• Lining the pan with parchment with the edges longer than the sides of the pan helps easy removal of the bars. Just lift them out when they are really cold using the drapes as handles.
• Cut them into squares after removing from the pan.

Enjoy!