Step 1

1 Combine the shortening and butter in the bowl of a stand mixer or hand-held electric mixer

Step 2

2 Beat on medium speed until smooth

Step 3

3 Reduce the speed to low; add the eggs and beat until well incorporated, stopping to scrape down the sides of the bowl as needed

Step 4

4 Heat the milk in a microwave-safe mixing bowl on LOW until the milk is just lukewarm, then add the yeast and stir until it has dissolved

Step 5

5 Add to the shortening mixture; beat on low speed to incorporate

Step 6

6 Stop to scrape down the bowl, then stir in the vanilla extract

Step 7

7 Sift together 4 cups of the flour, the baking powder and salt

Step 8

8 Add in batches to the shortening mixture, beating on low speed to form a sticky dough

Step 9

9 Lightly flour a work surface

Step 10

10 Transfer the dough there; knead the dough, adding some or all of the remaining flour until the dough no longer sticks to your hands

Step 11

11 Return to the bowl; cover tightly with plastic wrap and refrigerate overnight

Step 12

12 When ready to bake, position oven racks in the upper and lower thirds of the oven

Step 13

13 Preheat to 350 degrees

Step 14

14 Line several baking sheets with parchment paper or silicone liners

Step 15

15 Lightly flour a work surface

Step 16

16 Take a large handful of the dough and roll it in confectioners' sugar

Step 17

17 Roll the dough into a large square or rectangle about 1/4 inch thick

Step 18

18 Cut the square or rectangle into 2-to-3-inch squares

Step 19

19 Place a teaspoon of the filling in the center of each square

Step 20

20 Use the egg wash to brush two opposite, pointed ends of the dough, then pinch them together over the filling to form a small "danish" shape, making sure the dough is securely bonded

Step 21

21 (If not, the ends might open slightly as the cookies bake

Step 22

22 That is okay; only the looks and not the taste will be affected

Step 23

23 ) You also can brush all the points of dough, then pinch them in the center to form a small package; if desired, use a sharp knife to create a diagonal slash from each corner toward the center

Step 24

24 Arrange 3 inches apart on the baking sheets

Step 25

25 Bake for 20 to 25 minutes or until golden brown

Step 26

26 Transfer to a wire rack with several paper towels beneath it

Step 27

27 When the cookies have cooled a little but are still warm, sift a little confectioners' sugar over the tops of the kolache, if desired, to create a shiny coating

Step 28

28 Repeat to use all of the dough

Step 29

29 Cool completely before serving or storing (at room temperature, between sheets of parchment or waxed paper)