Mix the yeast with the warm water and let it sit for 5 minutes.
Combine the flour and salt. Add the butter and sugar to the yeast/water mixture and then slowly add to the flour and salt.
Knead for 2 minutes, until dough is smooth and elastic.
Rise in a covered, greased bowl for 1 hour or until dough is doubled in size.
After dough has risen, punch it down, and on a floured surface, roll it out into a 1/4-inch thick rectangle. Using a knife or pizza cutter, cut out 3 inch squares, and then cut squares on the diagonal into triangles.
Heat up 3 inches of oil in a big pot to 375° F. Fry 2 triangles of dough at a time in the oil for one minute on each side. The dough should puff when it hits the oil.
Remove the sopapillas from the oil with a slotted spatula and place on a paper-towel lined plate, sprinkle with with cinnamon and sugar, then serve hot with honey.