Making Wild Blueberry Coffee Cake Danishes involves several clear and straightforward steps. Follow these instructions to create your delicious pastries:

1. Prepare the Dough: In a large mixing bowl, combine flour, sugar, salt, and instant yeast. Mix well.

2. Cut in Butter: Add the cold, diced butter to the flour mixture. Use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.

3. Mix Wet Ingredients: In a separate bowl, combine warm milk and lemon juice. Let it sit for a minute. Then, gradually add this mixture to the flour mixture, stirring to form a dough.

4. Knead the Dough: On a floured surface, knead the dough until smooth, about 5 minutes.

5. Chill the Dough: Form the dough into a ball, wrap it in plastic wrap, and refrigerate for at least 1 hour.

6. Prepare the Filling: In a bowl, gently mix the wild blueberries with sugar, cornstarch, and lemon zest. Set aside.

7. Roll Out the Dough: On a floured surface, roll out the chilled dough into a rectangle about ¼ inch thick.

8. Cut the Dough: Cut the rolled dough into squares (approximately 4×4 inches each). You can make a notch in each corner to create a more elegant shape.

9. Fill the Danishes: Place 1 tablespoon of the blueberry filling in the center of each square.

10. Shape the Danishes: Fold the corners of the dough squares towards the center to enclose the filling. Pinch the edges to seal.

11. Prepare for Baking: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper and place the Danishes on it. Brush each pastry with beaten egg.

12. Bake: Bake for 25-30 minutes or until golden brown.

13. Prepare Icing (Optional): If desired, mix powdered sugar with milk until smooth to create a glaze. Drizzle over cooled Danishes.