Preheat oven to 375 degrees F. Grease muffin tins or line with paper liners.

In a large bowl combine the flour, oats, baking powder, and salt, mix together.

In another bowl whisk together the sugar, oil, eggs, milk, and vanilla.

Add the wet ingredients to the dry and mix just until combined.

Fold in the cranberries and pistachios.

For the topping

In a small bowl combine the brown sugar, flour, cinnamon, and butter and mix well.

Fill the muffin tins two-thirds of the way. Sprinkle the brown sugar topping over the top of each muffin.

Place in the preheated oven and bake for 18 to 20 minutes.

Cool completely and serve.