Preheat oven 350°F or 175°C. Line one 20 mini muffin tin with muffin paper or 12 original muffin tin.

Combine flour, baking powder, baking soda, and salt. Sift and set it aside.

Make streusel top: mix grated butter, sugar, and flour with fork. Put in the freezer before use.

With hand mixer, cream the cream cheese, butter, and sugar until fluffy. About 1-2 minutes.

Put the egg in, keep mixing it with slow speed. When it's Incorporated, add in buttermilk and vanilla. Continue mixing until, well mixed.

Mix in the dry ingredients all in once. Mix with wooden spoon for about 4 circle then add blueberries and cubbed cheese. Do not over mix the batter or the muffin will be dense.

Fill the prepared muffin tin with the batter until full. Put streusel on top.

Bake for 12-14 minutes. Poke with a skewer to check if the muffins are done. When the skewer comes out clean, the muffins are done.