Instructions

In food processor, process 2/3 cup granulated sugar and 1 1/2 teaspoons grated orange zest until pale orange, about 10 seconds. Transfer to small bowl and set aside.
In food processor, pulse dried apricots for ten 2-second pulses, until chopped fine. Transfer to medium microwave-safe bowl; add orange juice to apricots, cover bowl tightly with plastic wrap, and microwave on high until simmering, about 1 minute. Let apricots stand, covered, until softened and plump, about 5 minutes. Strain apricots; discard juice.
Adjust oven rack to middle position and heat oven to 400 degrees. Spray standard muffin tin with nonstick cooking spray.
Whisk flour, cornmeal, baking powder, baking soda, and salt in medium bowl to combine; set aside. Whisk eggs in second medium bowl until well combined and light-colored, about 20 seconds. Add granulated and dark brown sugar to eggs; whisk vigorously until thick and homogenous, about 30 seconds; add melted butter in 3 additions, whisking to combine after each addition. Add half the sour cream and half the milk and whisk to combine; whisk in remaining sour cream and milk until combined. Stir remaining orange zest and strained apricots into wet ingredients. Add wet ingredients to dry ingredients; mix gently with rubber spatula until batter is just combined and evenly moistened. Do not over-mix. Using an ice cream scoop or large spoon, divide batter evenly among muffin cups, dropping it to form mound. Sprinkle a portion of orange sugar over each mound of bater. Do not level or flatten surface of mounds.
Bake until muffins are light golden brown and skewer inserted into center of muffins comes out clean, about 18 minutes, rotating muffin tin from front to back halfway through baking time. Cool muffins in tin 5 minutes; do not invert baked muffins; use a paring knife to lift muffins from tin one at a time and transfer to wire rack. Cool muffins 5 minutes longer; serve warm.