Line a standard sized muffin tin with cupcake liners, set aside. Preheat your oven to 200 C.
In a medium sized bowl add all the wet ingredients: egg, melted butter, milk, yoghurt and vanilla along with the sugar. Using a whisk, mix well until combined.
Sift the flours, baking powder & soda, salt into this bowl and then add the chocolate chips. Gently fold until combined. Do not over-mix.
Using a spoon or an ice cream scoop, portion out the muffin batter into the prepared pan. You can fill the batter almost all the way up, this gives the domed muffin top.
Add around 2 tsp of streusel on top of each muffin batter portion and more chocolate chips if you like. (recipe of streusel in questions above the recipe).
Bake at 200C for 5-6 minutes and then reduce the oven temperature to 175C and bake for another 13-15 minutes. The total baking time will be 18-22 minutes depending on your muffin pan and oven temperature.
A skewer inserted into the middle of the muffin will come out clean.
Let the muffins cool inside the pan for 20-30 minutes before removing from the pan and cooling completely.
I like enjoying these muffins warm. Enjoy! (Please read the frequently asked questions above to solve any doubts).