In medium bowl, mix together flour, oats, sugar, baking powder, and salt. Using pastry blender or two knives, cut margarine into dry ingredients, until mixture looks like fine crumbs. Stir in eggs, sour cream, apricots, and milk.
Turn dough onto lightly floured surface. Knead lightly 10 times. Roll or pat into 10- x 11-inch rectangle. Cut into two 5- x 11-inch sections.
Mix streusel ingredients with a fork and lightly pat onto one piece of dough; cover with other piece.
With sharp knife, cut into triangles. Place on ungreased baking sheet; brush dough with reserved beaten egg. Bake 10 minutes or until golden brown. Immediately remove from baking sheet to wire rack. Serve warm or cold.