In a large pan, fry the bacon until nicely crisped, drain on paper towels and set aside. Pour off the fat and add the spinach to the pan.

Cook the spinach over medium heat, stirring frequently, until all of the liquid has evaporated, 5 minutes. Add the apple cider vinegar and sugar and cook until the sugar is thoroughly dissolved. Season to taste with salt and pepper.

Increase the heat to medium-high and add the butter and heavy cream. Continue cooking, stirring constantly, until the butter has melted and the cream is blended into the spinach, 2 minutes. Taste and adjust the seasoning if needed. Transfer to a serving bowl.