• Preheat the oven to 375℉. Line the muffin tin with 12 liners and set aside. Shred the zucchini with a grater on the coarse side and set aside.
  1 1/2 cups zucchini

For the streusel

• In a small bowl, make the streusel. Combine flour, white sugar, and cold cut up butter. Using your hands, mix it together until combined into a crumbly, streusel mixture. Set aside while you make the muffin batter.
  3/4 cup all-purpose flour, 1/3 cup white sugar, 5 tbsp butter

For the muffins

• In a large bowl, add in the sifted flour, baking soda, white sugar, cocoa powder, salt, and baking powder. Mix together and set aside.
  2 cups all-purpose flour, 1 1/3 cups white sugar, 1/2 cup unsweetened cocoa powder, 1 tsp baking soda, 1 1/2 tsp baking powder, 1/4 tsp salt
• Into a large bowl add oil, eggs, vanilla, and sour cream. Whisk until well combined.
  2/3 cups oil, 3 large eggs, 2 tsps vanilla, 1 cup full-fat sour cream
• Add the wet ingredients into the dry and using a spatula, gently fold to create a soft muffin batter. Mix until there are almost no flour streaks left.
• Add the shredded zucchini and chocolate chips and mix in a few times. Don't over-mix!
  1 1/2 cups zucchini, 2/3 cups mini chocolate chips
• Evenly divide the batter between 12 liners. Sprinkle a handful of streusel on top.
• Bake the muffins at 375°F for 20-25 minutes. The muffins are ready when a toothpick inserted comes out clean with no wet muffin batter.
• Serve them warm, or wait for them to completely cool, and enjoy!