In a small mixing bowl, combine the brown sugar and ground cinnamon, ensuring they are evenly blended.

Pour in the melted butter and stir the mixture thoroughly until well combined.

Gradually add the flour, mixing until the ingredients form a crumbly texture. The mixture should hold its shape when pinched between your fingers.

Sprinkle the prepared crumble mixture generously over cakes, breads, or fruit-based desserts before baking.

For an elegant touch, dust with powdered sugar before serving.