In a separate smaller bowl, combine buttermilk, oil, molasses, egg and vanilla. Mix well.
½ cup buttermilk, ¼ cup oil, 3 tbsp molasses, 1 large egg, 1 tsp vanilla extract
Pour wet ingredients into dry ingredients, mixing until just combined. Do not over-mix or your donuts could be tough. Batter should be lumpy.
Spoon batter equally into the 6 donut pan cups.
Bake for 12-14 minutes, or until a toothpick inserted into a donut comes out clean.
For the glaze, melt chocolate and butter in a bowl set over a saucepan of simmering water, stirring until smooth. Remove from heat, and stir in milk and corn syrup. Use immediately.