Preheat oven to 350F. Line a loaf pan with parchment paper and set aside.
Sift together the dry ingredients in a medium bowl and set aside.
In a large bowl, beat together the eggs, maple syrup, oil, milk, yogurt, and vanilla extract until well combined.
Add the dry ingredients to the wet and mix until just combined with a few flour streaks remaining.
Fold in the chocolate chips.
Combine the cinnamon and coconut sugar in a small bowl.
Spread half the batter in the prepared loaf pan then sprinkle the cinnamon-sugar over the batter. Scoop the remaining batter on top. Use a knife or chopstick to swirl the cinnamon-sugar into the batter completely. Be sure to get to the edges and bottom and top of loaf.
Add more chocolate chips on top if desired and bake for 40-45 minutes, until a toothpick inserted in the middle of the loaf has a few crumbs on it.