Step 1

Line 2 baking sheets with parchment paper.

Step 2

To make the peanut butter fudge filling, beat together the peanut butter, 2 tablespoons butter, powdered sugar and vanilla in a mixing bowl until smooth and creamy. Set aside.

Step 3

In a large mixing bowl, combine the flour, cocoa powder, sugar and salt. Add chunks of the butter and mix with a pastry blender or your fingers until the mixture is crumbly. Gradually add the water until the mixture is moistened and a dough forms. Place the dough in between two large sheets of parchment paper or onto a lightly floured surface. Then roll out into a 1/8-inch thickness. Cut the dough into rectangles, about 6 1/2 x 4 1/2 inches. Place a heaping tablespoon of the peanut butter filling on one half of the rectangle. Lay the other half of the dough over the filling and seal the edges by crimping with the back of a fork. Repeat until all the dough has been used, saving the scraps and re-rolling to make more rectangles. Cover the baking sheets and place in the fridge for 30 minutes to 1 hour.

Step 4

Preheat the oven to 400 degrees F.

Step 5

Bake the pop-tarts for 10 to 12 minutes. Cool completely before frosting.

Step 6

While the pop-tarts cool make the frosting. In the bowl of stand mixer, mix the powdered sugar, meringue powder, vanilla, cocoa powder and 3 tablespoons water for about 7-10 minutes on medium speed, until peaks begin to form. Stir in the melted chocolate. If your frosting seems too thick, add water to thin. I found 5 tablespoons of water was good.

Step 7

Spoon a thin layer of the frosting on top of the cooled pop-tarts. Allow frosting to harden 10 minutes and then if desired drizzle with warmed peanut butter and sprinkle with course salt or course sugar. Place on a baking sheet and allow the tart to harden uncovered, about 2 hours. Store in a sealed container for up to 1 week.