1/4 cup butter, softened
1/4 cup rice flour
1/4 cup tapioca flour
Heat oven to 425°F. Combine butter and sugar in large bowl. Beat at medium speed, scraping bowl often, until creamy. Add eggs; mix well. Stir in sour cream and milk. Reduce speed to low; add all remaining ingredients. Beat just until mixed.
Pour batter into greased muffin pan. Bake for about 12-18 minutes or until golden brown and toothpick inserted in center comes out clean. Serve warm.