Its easy to learn how to make homemade danish pastry dough, and, oh my goodness, does it take your baking to the next level.
In a stand mixer, mix together the flour, sugar, and salt for 10-15 seconds, or until combined. Scatter the butter chunks over the top and mix on low speed for 1-1 1/2 minutes, or just until the flour is no longer bright white, and lumps of butter the size of pecans are visible throughout.
In a small bowl, whisk the egg yolks and milk together until blended. Add to the flour mixture, all at once and mix on low speed for about 30 seconds. You will want to mix, just until the dough barely comes together. It should look really haggy.
Scoop the dough out of bowl and place onto a work surface (unfloured). Push dough into one mound and start to "smear the dough", by pressing down with your palm from the top of one side of the mound to the bottom. This process will smear the cold butter chunks into the dough. Only do this once or twice on each side of the mound of dough, until there are streaks of butter running through, rather than chunks.
Scoop up the dough with your hands and wrap tightly in plastic wrap, while pressing the dough down into a flattened disk shape, about 1 inch thick. Refrigerate for at least 4 hours before using. You can leave the dough in the fridge for up to 4 days.
Remove dough from fridge and divide in half. Press each half into a rectangle, and place on a lightly floured surface. Roll each half out forming a 14x11 rectangle.
Using a paring knife, score one half into 8 3 1/2 by 5 1/2 inch rectangles. Add about 2 tablespoons of raspberry jam in center of each scored rectangle.
Take the second 14x11 rectangle, score into 3 1/2 by 5 1/2 inch rectangles and brush with egg. Lay the entire rectangle on top of the first rectangle with the scoops of jam. Using your fingers, press down around each jam mound, so that the jam is trapped. Then, using a sharp knife or pizza roller, follow the score lines and cut out 8 rectangles.
Place rectangles on baking sheet at least an inch apart and bake for 40-45 minutes until the top of the pastries is golden brown. Let cool on the baking sheet for 30 minutes.
In a small bowl, whisk together the powdered sugar, vanilla and enough water to make a smooth, pourable glaze. After the 30 minute cooling time, bush the tops of the pastries evenly with the glaze.
Let the pastries stand for 10-15 minutes to allow glaze to set. Enjoy!!
Adapted from Flour, by Joanne Chang