Closely adapted from Bake from Scratch. I toned down the espresso by 1 tablespoon in this recipe because my husband is not the biggest coffee fan. But if you love it, add some more.
Preheat the oven to 325 F. Thoroughly spray a 10-12 cup bundt pan with baking spray. If you use a smaller (10 cup) bundt pan, have a mini loaf or mini bundt pans ready for excess batter.
Whisk together the melted butter, sugar and vanilla bean paste in a large bowl.
Whisk in the milk and Kahlua. Then whisk in the instant espresso until it is dissolved.
In a separate smaller bowl, whisk together the flour, baking powder and salt.
Lightly beat the eggs and add them to the butter mixture. Whisk.
Add half the flour and whisk it in. Then add the remaining flour and switch to a silicone spatula. Mix until thoroughly incorporated.
Pour the batter into the prepared bundt pan. If there is extra batter, prepare the mini pans and the batter to them.
Bake until a cake tester inserted into the center of the cake comes out clean. For mini cakes, it will probably be around 20-30 minutes--just follow your common sense. For the larger bundt cake, plan on 60-75 minutes, depending on the size of the bundt. When the cake is ready it will also begin pulling away from the sides of the pan.
Let cool in pan for 10 minutes before inverting onto a cooling rack to finish cooling.
Divide the confectioners' sugar in half between 2 small bowls.
In one bowl, add the Kahlua and instant espresso. Whisk until smooth.
In the other bowl, repeat with the heavy cream.
Pour glazes over the cooled cake. Either swirl them as you pour, or if you have a flat top, use a tooth pick or chopstick to swirl together.
Let set before slicing.