Cream together butter and 2/3 cup flour.

Divide the mixture into 2 equal parts.

Roll each half between waxed paper into 6x12 inch sheets.

Refrigerate the sheets.

Mix dry yeast and 3 cups of flour.

Heat milk, sugar, and salt to 115°F (43°C).

Mix warm milk mixture into flour and yeast with eggs and extracts.

Stir for 3 minutes.

Knead in remaining flour until dough is firm and pliable.

Let the dough rest until doubled in size.

Cut the dough in half.

Roll each half to a 14 inch square.

Place one sheet of cold butter onto each piece of dough.

Fold the dough over the butter like a book cover.

Seal edges with fingers.

Roll each piece out to a 20x12 inch rectangle.

Fold into thirds, folding long sides over the center.

Repeat rolling and folding.

Wrap in plastic and refrigerate for at least 30 minutes.

Remove from refrigerator one at a time and roll and fold each piece two more times.

Return to refrigerator to chill before shaping.

Roll the dough out to 1/4 inch thickness.

Cut into squares and place filling in the center, or fold and cut into strips.

Shape into desired forms (e.g., filled diamonds, spirals).

Place danishes on an ungreased baking sheet.

Let rise until doubled.

Preheat oven to 450°F (220°C).

Brush danishes with egg white (optional).

Bake for 8-10 minutes until golden brown.