Combine milk and yeast, let proof 5–10 mins. Add sugar, eggs, butter, flour, salt. Knead to smooth dough. Let rise 1–1.5 hours.
Make topping: simmer butter, sugar, cream, and salt 3–4 mins. Stir in vanilla, pecans. Pour into greased 9x13 pan.
Roll dough into 14x9 rectangle. Spread butter, sprinkle sugar + cinnamon. Roll and slice into 12.
Place rolls over topping, rise 30–45 mins.
Bake at 350°F for 30–35 mins. Cool 5 mins, then flip onto tray.