In the bowl of a stand mixer fitted with a paddle or dough hook, combine 3.5 cups flour, 1/4 cup granulated sugar, 1 tsp salt and 2 tsp instant yeast. In a small bowl whisk warm water (1/4 cup), 1/2 cup whole milk and 1 large egg. With mixer on low, slowly add wet ingredients and mix until a shaggy dough forms. Add 3 tbsp softened butter and continue mixing 2–3 minutes until smooth and elastic (about 4–6 minutes total). If dough is too sticky, add up to 2 tbsp flour; if too dry, add 1 tbsp milk.

First chill

Turn dough into a lightly floured bowl, cover, and refrigerate 30 minutes to firm up slightly before laminating.

Prepare butter block

While dough chills, prepare the cold butter block for laminating: place 10 oz cold unsalted butter between two sheets of parchment and bash/roll into a 7x8-inch rectangle about 1/4-inch thick. Keep chilled in fridge until dough is ready.

Laminate (folding)

On a lightly floured surface roll chilled dough into a 10x12-inch rectangle. Place butter block in center offset so it covers middle third. Fold the sides of the dough over the butter like an envelope, sealing edges. Roll gently into a long rectangle about 8x20 inches (light flour as needed). Perform a book fold (fold both short ends into the center, then fold in half) or a simple tri-fold, then rotate 90 degrees. Wrap and chill for 30 minutes. Repeat roll-and-fold procedure two more times (total 3 turns), chilling 30 minutes between turns. The dough should be pliable and cold but not frozen.

Final chill and shape

After the last fold and chill, roll dough to about 1/4-inch thickness and trim edges to a neat rectangle approximately 12x16 inches. Cut into twelve 4x4-inch squares (or 8 larger danishes). Place squares on parchment-lined baking sheet, cover lightly with plastic and let proof at warm spot until puffy, about 45–60 minutes (time varies with room temp).

Cream cheese filling (optional layer)

While danish proof, beat 4 oz softened cream cheese with 2 tbsp powdered sugar and 1/4 tsp vanilla until smooth and spreadable. Transfer to a piping bag or small bowl. For each square, when ready to fill, gently press a shallow well in center and pipe or spoon about 1 tbsp cream cheese mixture into the well.

Mixed berry filling

Make the filling

In a small saucepan combine 2 cups mixed berries, 1/4 cup granulated sugar, 1 tbsp lemon juice and 1 tbsp cornstarch. Stir to combine. Cook over medium heat, stirring often, until berries release juices and mixture thickens, about 4–6 minutes. Stir in 1/2 tsp vanilla. Remove from heat and cool slightly — filling should be thick but spoonable. If using frozen berries, cook until thawed and sauce reduces.

Assemble: Spoon about 1 to 1.5 tbsp berry filling into the cream cheese well (or directly into the center if skipping cream cheese). Do not overfill — leave a border so filling doesn't leak during baking.

Finish & bake

Egg wash and bake

Preheat oven to 400°F (200°C). Whisk 1 large egg with 1 tsp water to make an egg wash and brush lightly around the edges of each danish (avoid the filling). Bake on the center rack for 15–18 minutes, until the pastry is golden brown and puffed and the filling is bubbly. If bottoms brown too quickly, rotate sheet or lower rack.

Glaze

While danishes cool slightly, make a simple glaze by whisking 1/2 cup powdered sugar with 1 tbsp milk or lemon juice until smooth. When danishes are warm (not piping hot), drizzle glaze over centers. Optionally garnish with a few fresh whole berries and a light dusting of powdered sugar.