Preheat oven to 400°F (200°C).

Combine bran and boiling water in a large bowl and let sit to soften.

In a separate bowl, mix vegetable oil, brown sugar, and white sugar until well combined.

Add eggs to the sugar mixture and stir well.

Stir in buttermilk into the wet ingredients.

In a separate bowl, whisk together flour, baking soda, and salt.

Add the dry ingredients to the wet ingredients and mix until just combined (do not overmix).

Fill greased muffin tins only halfway.

Bake for 20 minutes, or until a toothpick inserted into the center comes out clean.