10 tablespoons flour
2 cups super-fine sugar
2 large eggs
1 teaspoon vanilla, optional
4-5 tablespoons milk
Dissolve yeast in warm milk. Let stand in warm spot until bubbly, about 5 to 10 minutes. Mix sugar, shortening and salt in a bowl. Add egg, and beat together for 1 minute.
To egg-sugar mixture, add flour, then yeast mixture and vanilla, beating about 3 minutes (with dough hook or by hand).
Turn dough onto lightly floured board and knead 1 minute.
Place in a lightly greased bowl, cover with a towel and let stand in a warm place to rise 1 hour or until double.
For the topping, cream butter in a mixer. Mix together flour and sugar; gradually beat into butter.
Add eggs, one at a time, beating well after each addition. Add vanilla.
Gradually add just enough milk to bring mixture to an easy spreading consistency, being careful not to make it too runny. Set aside until dough is ready for use.
When dough is doubled in size, punch it down and divide in two sections.
Roll or pat halves into bottom of two well-greased 8-inch square pans or one 13-by-9-inch pan. Crimp edges halfway up sides to hold topping. Prick dough with a fork to reduce bubbling.
Spread topping evenly over dough. Let stand 20 minutes.
Bake in a preheated 375 degree oven for 25 to 30 minutes for the 13-by-9-inch pan or 20 minutes for the 8-inch pan or until top is just golden and crusty, but still gooey. Do not overbake. Let cool in pan before cutting.