• mixing bowl
• fork
• (you can use a 2 cup food processor if you want)

• 1 cup brown sugar
• 1/2 cup all-purpose flour
• 1/3 cup butter, softened to room temperature
• 2 tsp ground cinnamon (only if you want a cinnamon flavor)

1. combine all the dry ingredients in a mixing bowl (or in the food processor)
2. add butter and, using the fork, combine all ingredients until the mixture resembles bread crumbs. (pulse in food processor until the correct consistency)

Do NOT add more butter, even though it looks like there is no way that there is enough. It is exactly the right amount.