Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners or lightly spray it with non-stick spray.
In a blender, combine the fresh spinach and milk, blending until smooth and vibrant green.
1 cup all-purpose flour
In a large mixing bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt until evenly combined.
1 cup all-purpose flour
Add the vegetable oil, eggs, vanilla extract, and the blended spinach mixture to the dry ingredients. Whisk everything just until the batter is smooth and uniform, being careful not to overmix.
1 cup all-purpose flour
Gently fold in the chocolate chips, distributing them evenly throughout the batter for gooey bursts of chocolate in each muffin.
1 cup all-purpose flour
Spoon the batter into the prepared muffin tin, filling each cup about three-quarters full for room to rise.
Bake in the preheated oven for about 18-20 minutes, or until a toothpick inserted into the center comes out clean and the muffins have risen with a slightly cracked top.
Remove the muffins from the oven, and let them cool in the tin for a few minutes before transferring to a wire rack to cool completely.
Once cooled, enjoy these tender, moist muffins with a hint of green and rich chocolate flavor, perfect for breakfast or a snack.