Combine milk and vinegar and let stand until milk sours.
Meanwhile, mix dry ingredients together with a wire whisk so that they are well combined.
Add soured milk, eggs, butter, oil, and vanilla. Beat together until smooth. Stir in grated carrots and raisins.
Bake in greased muffin tins at 420 degrees for 12 to 14 minutes until golden and cooked through. Makes 2 dozen muffins.
Equally good when half-rule is made. Also can be made non-gluten-free by using all-purpose flour and omitting xanthan gum.
Alternatively, you can bake this in a Bundt cake pan for about 1 hour. Top with Powdered Sugar Glaze.
Notes
This recipe was made with Saco Pantry Cultured Buttermilk Blend, which can be found in the baking aisle. Use it dry; do not add additional water. This is optional, but it does improve the texture.