In the bowl of a stand mixer, add milk, eggs, sugar, salt, vanilla. Attach the dough hook and mix on low for 1 minute.
Slowly add the flour and yeast and mix until slightly sticky. Add the softened butter. Increase the speed to medium and keep mixing for about 10 minutes. If you do not have a standing mixer you can mix the dough by hand a little longer until the dough is not sticking to your hands. The dough should be smooth and elastic after kneading.
When the dough pull away from the sides of the bowl and form a soft ball stop the mixer and cover the bowl with a plastic wrap. Let the dough rise until double in size for about 45-60 minutes depending on the room temperature.
Turn the dough onto a floured surface and divide into 8 equal portions. Using a scale makes things easier.
Roll each piece of dough on a long log, double in length as the length of your tray. Grab the log from the middle, fold it in half and twist both halves around each other. Place the breadsticks on silicon baking mat or parchment-lined 30x40 cm baking sheet. Cover the breadsticks lightly with kitchen towel and let them rise at room temperature for about 25-30 minutes.
Meanwhile in a small bowl make the topping. Combine the white and brown sugar with the cinnamon.
Toward the end of rising preheat the oven to 350F/176C.
Brush the breadsticks with apple sauce and sprinkle the cinnamon sugar mixture across the breadsticks.
Bake for 20-25 minutes or until light golden brown.
Enjoy!