Panderos are cookies prepared with almidón dulce* (sweet cassava starch or yuca flour). Originally from the Valle del Cauca region, they are sold by the highways there, in the Viejo Caldas area of the country, and the rest of the Andean highlands.
Preheat the oven to 375º F. Place the starch, sugar, panela, baking powder, and salt in the food processor and mix for 10 seconds. Add the egg, Aguardiente, and the fat of your choice, and process for 2 minutes.
Remove the dough from the processor and place on a work surface sprinkled with starch or flour. The dough will look very shiny; if you have trouble rolling it, add 1 tablespoon more starch and mix by hand.
Turn 2 or 3 times until you have formed a log. Cut into 4 pieces and roll each one into a log 1 inch wide by 10 inches long. Cut into 1-inch squares and mark each cookie with a fork pressing horizontally.
Butter a baking sheet and place the cookies on it. Bake for 15 minutes. The cookies will look pale on top and lightly golden on the bottom.
Let cool. Serve or store in airtight tins.