Preheat the oven at 350 F. Brush the jumbo muffin tin or a regular cupcake tin with some butter or oil and set it aside.
In a bowl, mix all the chopped berries. Divide berries evenly in the bottom of muffin cups and put in the oven for exactly 10 minutes.
In a large bowl, using hand mixer or whisk cream together butter and sugar till it turns light yellow in color. You can also use standing mixer.
Add vanilla extract and eggs to it and mix it thoroughly.
Add flour, baking powder and milk to it and mix it for a minute or till a smooth battar is formed.
Using a icecream scoop, divide the battar evenly in muffin cups.
Bake it for 20-23 minutes.
Once baked, allow it to cool for 10-15 minutes in the pan itself. Invert it into a plate.
Serve with some whipping cream or vanilla icecream.