Preheat oven to 375 degrees F.
In a measuring cup add 1 cup whole milk and 1 tbsp white vinegar. Stir. Set aside.
Mix all dry ingredients together.
Cut softened butter into the dry ingredients.
Add the curdled milk and egg.
Mix just until it comes together. If it's too dry, add 1 tbsp of milk at a time until it comes together.
Turn onto a floured surface.
Knead until a soft ball of dough forms. Only a few turns.
Place on baking sheet either lined with parchment paper or sprayed with olive oil.
Bake in preheated oven for 45-50 minutes or until a toothpick comes out clean.
Allow to cool on a cooling rack before slicing.