In a medium bowl, work together streusel ingredients with fingers and set aside.
Dissolve yeast in warm milk; add sugar and egg. Use a little melted butter to grease 9 x 13 pan. Mix in remaining butter. Gradually add flour and salt until it doesn't stick to fingers. Spread the dough into the pan with a small edge to it.
Mix apples, cinnamon and sugar. Place on top of dough. Sprinkle streusel over top.
Bake at 350° for 35 - 45 minutes or until golden brown.