These savory delights are a two-bite combination of crust on the outside, and a soft, tangy inside. The unexpected ingredient, coffee, adds depth of flavor that will surprise you.
Preheat oven to 400 degrees F. Using a pastry brush, spread melted butter on each cup of a 24 mini muffin tin, then coat the cups with the cracker or breadcrumbs. Set aside. Divide the remaining melted butter about in half.
Put the potato cubes in a pot. Add cold water to about 1-inch above the cubes, cover and bring it to a boil. Uncover, lower the heat, and cook until you can pierce the potatoes with a fork, about 10 minutes after the water reaches a boil. Immediately drain the potatoes and put them back in the hot pot, tossing it for a few minutes just to let the last bit of moisture evaporate.
With half of the melted butter that remained after preparing the muffin tins, add the milk/half and half and the coffee. Warm those liquid ingredients and then pour them over the potatoes. Mash the potatoes.
Add the sour cream, half the shredded cheese, and the minced chives/scallions. As the mixture cools down, get ready to fill the mini muffin tins.
Using two teaspoons, put a small ball of mashed potato mixture into each mini muffin tin. Press down slightly, add most of the remaining cheese, then top off with a tiny piece of mashed potato mixture, followed by a dab of melted butter and a tiny sprinkle of shredded cheddar cheese. The photo shows the various stages from right to left in the first row.
Bake the mini muffin cups for 30 minutes in the center of the oven.
When they are done, let the potato cups sit in the muffin tin for a few minutes. Once the muffin tin has cooled down a bit, slip a sharp knife around the edges of any muffins that appear to be stuck in the tin or to each other. Gently turn the muffin tin over on a wire rack and let the muffins slide out.
Let the muffins cool down for a few additional minutes before serving.
You can find all kinds of advice from various authorities as to what type of potatoes to use and how to best prepare them mashed. The general rule is that starchy Russet/Idaho/baking and/or Yukon gold potatoes work better than red ones for mashed potatoes. Cutting them into cubes makes the cooking go faster. If you want to leave the skins on, that's fine, as long as you wash the skin well.
It doesn't matter if you use "regular" or decaf coffee as long as the coffee is strong. I prefer a French or Italian Roast, but other dark or medium dark coffees should be fine too.
Do not be concerned if the mashed potato mixture mounds high in the muffin tins. As they bake, the mounds flatten.