Dissolve yeast in warm water. Stir in milk, sugar, oil, baking powder, salt, egg, and 3 cups flour. Beat until smooth. Mix in the remaining flour. Knead 8–10 minutes. Place in a greased bowl, cover, and let rise until double (about 1½ hours).
Grease two 9″x13″ pans. Punch the dough down and divide it in half. Roll half into a 10″x12″ rectangle. Spread butter and sprinkle with the filling mixture, half on each dough. Roll up. Cut into slices.
Cover pan tightly with foil. Refrigerate overnight.
Bake uncovered at 350°F for 20–25 minutes.
Mix together caramel topping ingredients. Pour over rolls to serve.
Notes
Pour a little boiling water over the rolls just before baking.