Add 3/4 cups lukewarm milk plus 2 tablespoons water to a bowl. Sprinkle yeast over top and allow to proof for about 5 minutes, until foamy. (Do this in the bowl of a stand mixer, or in a large mixing bowl if you're working by hand.)
In a small bowl, add sugar and orange zest. Massage the sugar and zest together with your hands for about a minute to release the citrus oils for extra flavor.
Add in orange sugar, vanilla, softened butter, and optional brandy, and whisk to combine. Then add in flour and salt.
Stir with a wooden spoon or spatula until dough comes together in a shaggy ball. (Stand mixer: Mix with the paddle attachment until everything comes together in a shaggy dough.)
Turn dough out on a lightly-floured surface. Knead 8-10 minutes. A bench scraper can be helpful to keep the dough from sticking to the surface as you develop the gluten. (Stand mixer: Switch to the dough hook attachment and knead for 5-8 minutes. The dough should become smooth and elastic and "clean" the sides of the bowl.)
If the dough feels excessively sticky or wet, or it's sticking to your hands too much when kneading, you can sprinkle on extra flour. Add more flour 1-2 tablespoons at a time, kneading to incorporate between additions, until you achieve the correct texture. Knead until dough is smooth and elastic.
Shape the kneaded dough into a ball and transfer to a lightly oiled bowl. Cover with plastic or a clean, damp kitchen towel. Allow to rise in a warm place until at least doubled in size. This usually takes around 1 1/2 hours, but it will vary based on the temperature of your kitchen. If it's very chilly, it can take up to 2 hours.