In a medium saucepan melt butter and evaporated milk over low heat.
Add cinnamon and sugar and stir until sugar is dissolved. (It's important to keep stirring until the sugar mixture is completely dissolved or you risk burning the bottom which will create white stringy/chunky thing (technical term)).
Put in an airtight container or bell jars (perfect for gift giving). Refrigerate
To use, put a little in a bowl and heat up in the microwave for 5-10 seconds. Super yummy to spread on toast!