Cream butter and ⅔ cup flour in a medium bowl until well combined. Divide into two equal parts, then roll each half between two pieces of waxed paper into a 6x12-inch sheet. Chill butter sheets in the refrigerator.

Mix 3 cups of flour with active dry yeast in a mixing bowl; set aside.

Stir together milk, sugar, and salt in a small saucepan over medium heat until the mixture becomes warm (about 115°F or 43°C).

Pour warmed milk mixture over the flour-yeast mixture. Add eggs, lemon extract, and almond extract. Stir for 3 minutes. Knead in the remaining flour, ½ cup at a time, until the dough is firm and pliable. Cover and let rise until doubled in size (30–60 minutes).

Cut the dough in half. Roll each half into a 14-inch square. Place one cold butter sheet on one side of the dough square, fold the dough over the butter sheet like a book, and pinch its edges together.

Roll the folded dough into a 20x12-inch rectangle and fold into thirds like a letter. Repeat rolling and folding. Wrap in plastic and refrigerate for at least 30 minutes.

Repeat the rolling and folding process two more times for each dough piece. Refrigerate finished dough for at least another 30 minutes.

Roll the chilled dough out to ¼-inch thickness. Cut into squares. Place a dollop of fruit preserves in the center of each square and fold two opposite corners over the center to form a diamond.

Allow the formed pastries to rise at room temperature until doubled in size, about 30 minutes.

Preheat the oven to 450°F (220°C). Brush the pastries with beaten egg white.