For the Bolillo: Using an electric mixer with a dough hook, whisk the yeast, sugar and warm water for 2 minutes to dissolve the yeast. Add 1 1/2 cups of the flour. Let sit for 1 hour. With the mixer on low, add the butter, salt, flour and cinnamon. Mix until the dough starts to come together. Increase the speed to medium-high and mix until the dough comes away from the sides of the bowl and crawls up the dough hook. The dough will be sticky. Grease a mixing bowl with the oil. Place the dough in the greased bowl and turn to coat. Cover the bowl with plastic wrap and place in a warm, draft-free place until the dough doubles in size, about 1 hour. Remove the dough from the bowl and invert it onto a heavily floured surface. Divide the dough into 12 equal portions. On a floured surface roll each piece into an oblong form. Tuck and roll so that any seams disappear into the dough. Gently pull the ends of each oblong, giving a slight twist as you pull. Place the rolls on a baking sheet and cover with a towel and let rise for 30 minutes, or until doubled in size. Preheat the oven to 375 degrees F. Bake for 10 minutes. Reduce the temperature to 350 degrees F and continue to bake for 20 to 25 minutes or until golden brown.
To assemble the Pambazo: Cut the Bolillo in half lengthwise and pull out the soft center from both sides. Heat a large skillet and cook, cut side down, for 1 minute. Remove from the skillet and flip over. Spread both sides of the bread with mayonnaise. Arrange the pork on one half. Top the pork with onions, tomatoes and avocados. Spread the beans on the other half of the bolillo and top with cheese. Close the sandwich. Place back into the skillet and continue browning while pressing down with a spatula. Flip and cook on the other side. Remove and serve.