Activate the yeast in warm water with 2 tsp of sugar.

Make dough: combine milk, remaining sugar, mashed potatoes, butter, egg yolk, salt and vanilla; add 1 c flour; pour in activated yeast; add remaining flour; knead.

Shape dough into a ball with greased hands; cover with plastic wrap; let dough rise in a warm place until doubled in size.

While dough is rising, combine filling ingredients in a bowl together.

Once the dough has doubled, punch it down.

Roll dough out into a large rectangle; dollop filling mixture on top; spread out into an even layer.

Roll dough up lengthwise; slice the dough into 12 even pieces; place on greased pan; cover and let rise.

Once doubled, bake at 350℉ for 18-22 minutes; cover with frosting while warm.