In a small saucepan on low heat, mix the butter, sugar, water, and cinnamon, stirring until the sugar dissolves and the butter melts.
Remove from the heat and add pecans, stirring until they are well coated.
To a parchment lined baking sheet, add the pecans and bake at 330 F (165 C) for 20 minutes, stirring halfway through.
Remove them from the oven and allow them to cool fully before using. Store them in a glass container for up to two weeks.