Preheat the oven to 400°F (200°C). Place the 12 paper liners in a muffin pan.
Dissolve the instant coffee into the milk, add the vanilla extract and set aside. Melt the butter. Beat the eggs in a small bowl.
Place sifted flour, sugar, baking powder, cinnamon and salt into a large bowl.
Add melted butter, milk and eggs to the flour mixture and mix to combine. Do not overmix, some small lumps in the batter are ok.
Fold half of the chocolate chips into the batter.
Distribute the batter evenly among the muffin liners and sprinkle the remaining chocolate chips on top.
Bake on the middle rack of the oven for about 20 minutes. Remove the muffins from the pan and let them cool on a wire rack.
Notes
Expert tips:
Coffee Intensity: Adjust the amount of instant coffee based on your preference. Add a little more for a stronger coffee flavor or a bit less if you prefer a subtler flavor.
Don't Overmix: Mix the batter just until the dry ingredients are moistened. Overmixing can lead to dense muffins. Some small lumps in the batter are perfectly fine.
Bake Immediately: Once the batter is mixed, bake it immediately. Letting it sit can cause the baking powder to lose effectiveness, and your muffins will not rise properly in the oven.
Cooling: After removing the muffins from the oven, transfer them to a wire rack to cool.
Storage: These treats are best enjoyed fresh but will keep well in an airtight container at room temperature for up to 3 days. For longer storage, freeze them for up to a month.