• Preheat oven to 350 F (180 C) for conventional oven, 330 F (165 C) for convection oven. Line your muffin pan with liners

Prepare the toppings:

• Use a fork to combine all the ingredients for the streusel. There will be some uneven sizes of crumbles and that's okay. Keep it chill in the fridge while you prepare the batter
  

Prepare the filling:

• Combine all the ingredients for the filling
  

Prepare the muffin batter:

• Combine all the wet ingredients in a mixing bowl. Sift in the dry ingredients
  
• Use a rubber spatula to fold the dry into the wet while rotating the mixing bowl. It may be lumpy but as long as you don't see any dry bits of flour, you are done mixing. Do not overmix
  
• Scoop about 1 1/2 tablespoon of batter into each muffin liner.
  
• Top with the filling evenly for each one, about 2 teaspoon or less.
  
• Scoop the rest of the muffin batter evenly into each well.
  
• Sprinkle the topping evenly among the muffins. Lightly press on the topping with your fingers
  

Bake the muffins:

• Put the muffin pan on the center rack in the oven. Bake for 18-20 minutes or until a cake tester inserted into the center of the muffin comes out clean with just a bit of crumbs is okay as long as it's not wet. Do not overbake muffins. They will be dry

Cooling:

• They are still very fragile and soft when they are first out of the oven. Let the muffins cool in the pan for 5 minutes. Then carefully transfer them to a cooling rack to cool down further
  

Serving:

• The muffins can be served warm or at room temperature