Preheat the oven to 400ºF and grease a 12-cup muffin tin.

In a large mixing bowl, stir together oats, milk, apple butter, and eggs.

In a separate bowl, whisk together flour, 1/2 cup sugar, baking powder, baking soda, and salt.

Add wet ingredients to dry ingredients and mix until just combined.

Stir in raisins.

Spoon muffin mixture into greased muffin pan.

Sprinkle tops of muffin batter with sugar.

Bake in preheated oven for 20-25 minutes or until done.

Remove muffins onto a cooling rack.

Serve warm with butter!