This really is a delicious and moreish muffin recipe, with or without the crumble topping. No mangoes? You can also swap the mango with any roughly chopped, soft, seasonal fresh fruit.
Preheat oven to 180°C and grease or line a 12-hole muffin tray with paper cases.
Sift dry ingredients together in a large bowl.
In another bowl, whisk together the buttermilk, eggs, sugar and oil until well combined.
Gently fold the wet and dry ingredients together and add the mango, stirring until just combined.
Divide the batter between the muffin holes, filling them only 3⁄4 of the depth and top with a 1cm layer of crumble mix.
Bake for 25 minutes or until muffins are golden and cooked through.
For the crumble, mix the sugar, butter, flour, nut meal, salt and cinnamon together with your fingers, working the ingredients into a sand-like mixture.
Stir through the oats and chopped nuts and keep in the fridge or freezer until ready to use.