Combine boiling water and oats; allow to stand 5 minutes. In large mixing bowl, combine yeast and warm water, stirring to dissolve yeast. Add sugar, butter, celery salt, egg, softened oats and 2-1/2 C of the flour. Beat until smooth. Continue to add flour to make a soft dough. On floured board, knead 5 minutes. Cover and allow to rise 10 minutes. Press dough firmly into greased 13" x 9" baking dish. Use sharp knife to cut through dough to form desired roll shapes. Cover and allow to rise in a warm place until doubled in size, about 30 minutes. Brush with additional melted butter if desired. Bake at 375°F for 15 minutes. Combine remaining ingredients. Spread over bread. Cover with foil if necessary. Bake 10 to 15 minutes longer until golden.