Place the rum, cranberries, and raisins in a microwave-safe bowl, cover with plastic wrap, and microwave until the mixture is just warm. Set aside to cool to room temperature.

Once the mixture has cooled, place all bun ingredients (except the cranberry mixture) in the bowl of a stand mixer fitted with the dough hook. Mix on medium speed until dough is soft and elastic—about 4 to 6 minutes. Add the cranberry mixture along with any liquid the fruit did not absorb and mix until evenly distributed. (Dough will be very wet and sticky.)

Cover the bowl loosely with plastic wrap and allow to rise at room temperature for 1 hour. Dough will be puffy but will not necessarily appear to have risen much.

Lightly spray a 9- x 13-inch baking pan. Divide dough into about 12 (larger) to 15 (smaller) buns. Butter your hands to form them into balls and arrange in the prepared pan.

Cover the pan and let the buns rise for 1 hour, or until they’ve gotten puffy and smoosh into each other.

Preheat oven to 375 degrees. Whisk together egg wash ingredients and brush over the buns.

Bake for 18 to 20 minutes, until buns are lightly golden. Set pan on a wire rack to cool.

Once buns have cooled completely, stir together frosting ingredients. Pipe a cross shape onto each bun. Serve and enjoy.