Preheat the oven to 350 degrees. Prepare your mini-bundt pan by brushing each well with melted butter. Don’t skimp! There’s nothing worse than stubborn cakes.
In the bowl of a stand mixer {or using a hand mixer}, beat together the butter and sugar until pale and fluffy. Add in the tangerine zest and mix well.
Add the eggs, one at a time, beating well after each addition. {Don’t worry if it looks curdled at this point, it will come together.} Add the vanilla extract. Scrape down the sides of the bowl with a spatula to make sure everything is well incorporated.
Slowly mix in the cake flour and salt until just incorporated -- try not to overmix.
Spoon* batter into the mini-bundts, filling about ¾ of the way full and bake for about 12-14 minutes or until the cakes are lightly golden or a toothpick inserted comes out clean.
When the cakes are ready, remove from the oven and cool for about 5 minutes. Poke the cakes all over using a skewer or toothpick.
While the cakes are still warm, pour about 1 tablespoon {or more if needed} of the cake syrup {see recipe below} over the top of each cake. Let it soak in for about 5 minutes or until the liquid is absorbed.
Place an inverted cooling rack on top of the pan, then swiftly flip to release cakes onto the rack. {This may take a little tap or two on the countertop for any cakes that are being stubborn, but if you buttered sufficiently they should all pop out.} Let cool completely before glazing.
*I found the easiest way to “spoon” the batter in was not to use a spoon at all! Simply fill a zip-top bag with the batter, snip one of the corners, and pipe the batter into each cake mold.
For Glaze: In a small bowl combine the ingredients and stir until smooth. If your glaze it too thick, add a bit more liquid until the desired consistency is reached. For best results, try for thicker glaze that will “stick” to your cake.
Drizzle or dip cakes to cover with glaze, then place on a cooling rack, allowing the excess to drip off.
If desired, sprinkle each cake with sparkling sugar and/or edible sugar pearls while the glaze is still wet. Let glaze set slightly before serving.