Preheat oven to 350. Line a 12-cup muffin tin with paper liners.
In a large bowl, whisk together the eggs, oil, and sugars until pale. Whisk in the cocoa powder, flour mix, baking powder, soda, salt, vanilla and milk until smooth, set aside.
In a medium bowl, mix together the shredded coconut and sweetened condensed milk. With damp hands, roll into 12 even balls, about 2 teaspoons of batter each.
Fill each muffin cup 1/2 full with the chocolate batter, then place a coconut ball in the center of each and cover with the remaining chocolate batter.
Bake until a toothpick inserted in the center comes out clean, 20 to 25 minutes. Let cool 5 minutes in the tin, then transfer to a wire rack to cool completely.
In a medium saucepan, heat the heavy cream until hot but not boiling. Remove from heat, and stir in the chocolate until melted and smooth.
While the glaze is still warm, top each cupcake with the chocolate glaze, and sprinkle nonpareils in the center of each. Let the glaze cool before serving.