Mixed Berry & Lemon Chocolate Tart

This should be titled "My failed attempt at making a tart"! I had planned on making a variation of this as our dessert for Easter, but after I finished making it, I vowed to never make a tart again! Everything that could have went wrong while making this tart did go wrong! First, my dough looked nothing like the dough in the picture on Ceramic Canvas, hers looks so pretty! Then, my berry mixture didn't set in the fridge like I assume it should have. When I poured the lemon custard on top, rather than layering, the berries and lemon mixtures swirled together. The two layers then decided to overflow onto the baking sheet underneath it, making a mess! Lastly, it took forever to set up in the oven. I don't think it actually ever did. My mom kept telling me it looked good anyway, and my mother-in-law came up with the idea to throw it in the freezer to set up while we were eating dinner. It turned out to be slightly messy but tasted pretty good.

Chocolate Tart Shell
10 tablespoons Unsalted Butter, cold and cubed
3/4 cup Sugar
1/8 teaspoon Kosher Salt
1 Large Egg
2 1/2 cups Flour
1/2 cup Unsweetened Cocoa Powder
1 teaspoon Baking Powder

Put the butter, sugar, and salt in the bowl of a stand mixer fitted with the paddle and beat until until pale. In a separate bowl, whisk the egg and add to the butter mixture, scraping the bowl often. Whisk the flour, cocoa powder, and baking powder together and add to the wet ingredients, mixing on low, until blended. Dump the dough onto a lightly floured work surface and shape into a ball, then flatten into a disc. Wrap the dough in plastic wrap and refrigerate for at least an hour. When ready to use, roll the dough between 2 pieces of parchment paper until it is about 1/8 of an inch thick. Press the dough into a tart pan, making sure to cover all corners of the pan. If the dough breaks apart, patch it up and press it into all areas of the pan. Prick the dough with a fork, line the tart pan with parchment paper, and pour in rice, beans, or pastry weights into the pan. Bake the tart until cooked through, about 15 minutes, at 375 degrees.

Mixed Berry Filling
13 ounce bag Frozen Mixed Berries, thawed
3/4 cup Sugar
1 1/3 cups Water

Combine the berries and water in a large saucepan and bring to a boil. Cook until the berries burst and the mixture thickens, about 8-10 minutes. Remove the mixture from the heat and blend the berries with an immersion blender until the mixture is fairly smooth. Stir in the sugar and set aside.

Lemon Custard
3 Lemons, juice and zest removed
1/3 cup Cornstarch
1 1/4 cup Water
3 Large Egg Yolks
6 tablespoons Sugar
1/4 teaspoon Vanilla Extract
4 tablespoons Butter, in small cubes

Put the zest and juice in a small heat resistant bowl placed over a pan with simmering water. Add the cornstarch and whisk in 2 tablespoons of water until you have a smooth paste. Add the remaining water, boiling hot, and continue to whisk over the simmering water until the mixture is thick and bubbling. Remove the bowl from the heat and whip in yolks, sugar, vanilla extract, and butter. Let mixture cool slightly and set aside.

To assemble the tart:
Pour a layer of berry filling in the bottom of the pre-cooked tart shell. Refrigerate for about 20 minutes, until the berry mixture begins to set. Remove the tart from the fridge and add the layer of lemon filling on top, being careful not to mix or swirl the lemon filling with the berry base (like I did!). Place the tart pan on a baking sheet and bake at 375 degrees for about 20 minutes, or until the lemon filling has set. Remove tart and allow it to come to room temperature. Refrigerate after serving.