Preheat your oven to 350°F (175°C). Grease and flour the mini bundt cake pans.
In a mixing bowl, whisk together the flour and half of the sugar. In a separate bowl, whisk the eggs with the remaining sugar and vanilla extract until well combined.
Add the melted butter and milk to the egg mixture, stirring until smooth. Gradually fold in the dry ingredients until just combined.
Pour the batter into the prepared mini bundt pans, filling about 2/3 full.
Bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean. Let the cakes cool in the pans for 10 minutes, then turn out onto a wire rack to cool completely.
In a small bowl, mix the sweetened condensed milk, evaporated milk, and whole milk to create the soaking mixture.
Once the cakes are cooled, drizzle the milk mixture evenly over each mini cake, allowing it to soak in for at least 15 minutes.
Serve the Tres Leches Mini Bundt Cakes topped with fresh berries or coconut flakes if desired. Enjoy!