Preheat the oven to 350 degrees.
Grease your miniature Bundt pan molds; set aside.
Place the cake mix, flour, sugar, and baking powder in your mixer bowl. Using the paddle attachment, blend the dry ingredients for about 1 minute to thoroughly combine. You can alternatively use a hand-held mixer.
Add the eggs, orange juice, mayo, and zest. Mix the ingredients on the lowest setting for about 30 seconds, or until the ingredients are moistened. (You don’t want to start on medium and orange juice fly onto your counter.)
Mix the ingredients on medium speed for 2 minutes, stopping to scrape the bowl and blade as necessary, even if you have a silicone-edged blade.
Evenly divide the batter between the Bundt molds, filling just under 3/4 full.
Bake the pan(s) in the oven for 12 to 15 minutes, or until the cakes have risen and spring back when lightly touched.
Remove the pan(s) from the oven and allow to cool for about 10 to 15 minutes.
Invert the cakes onto a rack to completely cool, approximately 45 minutes to 1 hour.
Prepare the glaze. Blend all the glaze ingredients in a bowl with a whisk. Add more orange juice to thin out the glaze, or add more confectioners’ sugar to thicken to desired consistency. Evenly pour the glaze over the completely cooled mini Bundt cakes. Garnish with strips of zest if desired.
If any leftovers, store in an airtight container for up to 4 days. Or, place in an airtight container and freeze for up to 3 months. Defrost at room temperature or in the refrigerator.