Preheat the oven to 425 F. Grab a muffin tin and line with 6 liners. Set aside.
In a small bowl, combine the brown sugar, flour and melted butter for the streusel topping. Use a spoon to mix everything toghether until it forms a crumble. If it's still too dry, add a bit more melted butter. Set the bowl aside.
¼ cup brown sugar, ¼ cup all-purpose flour, 1 ½ tablespoon unsalted butter, melted
In a medium bowl, add the melted buter, milk, sugar, vanilla, greek yogurt and the egg and whisk them together.
4 tablespoon unsalted butter, melted, ¼ cup plain, full-fat greek yogurt, ¼ cup milk, room temperature, ⅓ cup cane sugar, 1 teaspoon vanilla extract, 1 egg, room temperature
In a separate bowl, combine the flour, salt, baking powder, cardamom, and chocolate chips.
1 cup all-purpose flour, ¾ teaspoon kosher salt, 1 ½ teaspoon baking powder, ½ teaspoon cardamom, ½ cup semi-sweet mini chocolate chips
Pour the dry ingredients into the wet bowl and mix to combine. Stop mixing as soon as there are no more flour streaks!
Scoop the batter into each liner until ¾ths full. Top with the brown sugar streusel and a few more mini chocolate chips, bake for 5 minutes at 425 F, then lower the heat to 375. Bake for another 15-17 minutes, or until the tops spring back when touched.
Let cool and enjoy!