place the muffin liners in the muffin pan. also preheat your oven at 180 degrees celsius/350 degrees fahrenheit 15 minutes before you start baking. for baking in the convection mode of the microwave oven, use 170 degrees celsius/330 degrees fahrenheit as the preheat temperature.
take 75 grams unsalted butter or ½ cup roughly chopped chilled butter in a pan. keep the pan on a stove top and on a low heat melt the butter.
stir while the butter is being melted so that the butter melts quickly. just melt the butter. no need to heat the butter.
keep the pan down once the butter has melted. add 1/2 cup sweetened condensed milk. about 125 ml condensed milk.
with a wired whisk, begin to stir very well.
whisk very well to make a smooth homogeneous mixture.
now add the mango puree. mix again very well.
now take 1 cups whole wheat flour/atta, 1/2 tsp baking powder and 1/4 tsp baking soda, a pinch of salt directly in a sieve.
seive directly in the mango mixture bowl. you can also seive the dry ingredients separately in a plate and then add the flour mixture to the mango mixture.
with a spatula fold the dry ingredients into the wet ingredients. with light hands, gently fold. do not over do. the batter should have volume and should not fall flat or become doughy like chapati atta.
depending on the quality of flour, you might get a thick batter like i have got. this much thickness is fine. but if the batter looks very thick, then do add some tablespoons of milk. also mango puree made at home is usually thick. if you use store bought mango puree, then the batter will be slightly on the thinner side.
folding is the most important step and can make or break your mango muffins or cake. so do it properly.
with a spoon or a small spatula, add the batter in the muffin liners more than 3/4 volume of the liners. gently even the top with the spatula.