¾cup+ 2 tablespoon unsalted butterchilled and cut into ½" cubes
1 ½teaspoonwhite vinegar
2tablespoonegg whitesequivalent of half an egg + 1 tablespoon for brushing
¼cupcold water
¼teaspoonvanilla extract
For the Filling:
¾cupstrawberry preservesI used reduced sugar
1tablespooncornstarch
1tablespooncold water
¼teaspoonvanilla extract
For the Frosting:
½cup+ ⅛ cup confectioners' sugar
1 ½tablespoonmilk
¼teaspoonvanilla extract
1 ½teaspoonlight corn syrup
Sprinklesfor decoration
Instructions
For the Filling:
Stir together strawberry preserves (or preserves of your choice), cornstarch, water, and vanilla extract in a saucepan set over medium to medium-low heat. When mixture begins to bubble, let simmer for a few minutes, stirring occasionally. Remove saucepan from heat and let cool while you prepare the pastry dough.
For the Dough:
Preheat oven to 350°F. Grease a large cookie sheet and set aside.
Mix together flours, sugar, and salt. Pour dry mixture into a food processor, then add butter cubes straight from the fridge. Pulse in food processor until butter cubes have been reduced to small chunks (about ¼" wide) and are well-integrated with the dry ingredients. Alternatively, you can add dry ingredients to a mixing bowl and cut in butter cubes using two knives.
In a bowl, stir vinegar, 2 tablespoon egg whites, water, and vanilla extract together. If using the food processor method, turn out butter mixture into a mixing bowl. Pour the wet ingredients into the bowl with the butter mixture, and stir until ingredients are just combined. You should be able to press together the dough with your hands to form one large ball of dough. Divide it in two.
On a floured surface, roll out one half of the dough into a rectangular shape, approximately ¼" thick. Using a pastry cutter or sharp knife, cut out eight equally-sized rectangles of dough (or, pretty close to equal). Place rectangles equidistant from one another on the prepared cookie sheet, then brush remaining 1 tablespoon of egg whites around the edges of the dough rectangles (for adhering purposes).
Repeat the process of rolling out dough and cutting rectangles with the remaining dough. Keep these eight rectangles to the side for the time being.
Spoon approximately 1 ½ tablespoon of filling onto the bottom rectangles that are on the cookie sheet. Using the back of a spoon, slightly spread filling around dough rectangle, taking care to leave a good margin around edges to reduce the likelihood of the filling bubbling out on to the cookie sheet mid-bake. Despite the margin, a small bit of the filling busted out of a few of my Pop Tarts right at the end of their bake time, but it really wasn't a big deal. Just be cautious here (and cross your fingers!)
Press the eight rectangles cut from the second batch on top of the ones with the filling, and using your fingers or the back of a fork, press down on edges to seal. Using the tines of a fork, pierce a few holes in the top of each pastry to let air escape while baking.
Bake pastries for 20-22 minutes, or until tops of pastries are golden brown. Remove, and let cool on a wire rack.
For the Frosting:
Whisk together all ingredients, except for sprinkles, in a small bowl, adding milk a little at a time so frosting doesn't become too liquid-y. Once pastries have cooled, set them on a sheet of wax paper or on a wire rack set over paper towels. Spoon frosting over top of each pastry, then decorate with sprinkles. Frosting will harden in 10-15 minutes.
Nutritional information is provided as an estimate. As it can vary due to many factors (brands used, quantities, etc.), we cannot guarantee its accuracy.