Preheat oven to 400 degrees F. In a medium bowl combine the flour, sugar, and baking powder and mix well. In another bowl combine the sour cream, buttermilk, oil, eggs, and extracts and mix well. Make a well in the center of the dry ingredients and pour in the liquid ingredients all at once. Mix lightly until the mixture is just moistened. Add the lemon rind and poppy seeds, tossing lightly to mix.
Spoon ½ cup of batter into greased or paper-lined muffin tins. Bake 18 to 20 minutes until golden or until a toothpick inserted into the center of one of the muffins comes out clean. Cool the muffins in the pan for 5 minutes then remove to a wire rack.
Combine the glaze ingredients and drizzle over the muffins while they are still very warm.