Preheat oven to 325°.

In a large bowl, combine beat the brown sugar and shortening until well combined. Stir in the buttermilk, egg and vanilla until mixed well.

Add the flour, baking soda and salt to the bowl and mix well. Fold in the cranberries.

Line a muffin pan with cupcake liners and fill each one 2/3 full with batter.

Finely chop the pecans using a food processor or nut chopper. In a small bowl, mix together the cinnamon, sugar and finely chopped pecans to make the streusel.

Top all of the muffins with a spoonful of streusel mixtures.

Bake at 325° for 30 minutes, or until a toothpick inserted in the center comes out clean.

Allow to cool to room temperature before storing in an airtight container.