Preheat the oven to 350 degrees F. Grease and flour a 12-cavity mini bundt pan using Baker's Joy spray or melted shortening and a dusting of cocoa powder. Tap out any excess.

In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

In a separate bowl, whisk the milk, oil, eggs, and vanilla until smooth. Gradually pour the wet ingredients into the dry mixture, stirring until just combined.

With the mixer on low, slowly add the hot coffee and mix until the batter is smooth. Fold in the mini chocolate chips if using.

Transfer the thin batter into a piping bag or a large measuring cup with a spout. Fill each bundt cavity about two-thirds full.

Bake for 22 to 26 minutes, until a toothpick inserted into the center comes out clean. Let the cakes cool in the pan for 10 minutes, then turn them out onto a wire rack to cool completely.

In a microwave-safe bowl, combine the sweetened condensed milk and chocolate chips. Microwave on high for 1 minute, then stir until smooth. If needed, heat in 15-second bursts until fully melted. Let the ganache cool slightly.

Spoon the ganache over the cooled mini bundt cakes. Garnish with sprinkles, berries, or whipped cream if desired.