Preheat oven to 350°. Brush a 12-hole muffin tin with butter.
In a small bowl, combine the sugar and cinnamon. On a work surface, cut each biscuits up into 4 equal size pieces. Roll each piece into a thin circle. Brush one piece of dough with butter and sprinkle generously with cinnamon sugar mixture. Top with another piece of dough. Repeat, stacking about 5 or 6 pieces. Then fit, standing up, into one of the prepared muffin tins. Repeat with remaining dough.
Sprinkle tops of each muffin with remaining cinnamon sugar.
Bake until golden and puffed, about 18 to 20 minutes. Serve warm or at room temperature.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2020/04/28/churro-pull-apart-muffins/