Preheat the Oven: Set it to 350°F (175°C) and line a muffin tin with paper liners or grease it lightly.
Mix Dry Ingredients: In a medium bowl, whisk together flour, baking powder, baking soda, salt, espresso powder, and cinnamon.
Combine Wet Ingredients: In a large bowl, whisk Greek yogurt, honey (or maple syrup), melted coconut oil, eggs, vanilla extract, and brewed espresso until smooth.
Incorporate Dry Ingredients: Gradually stir the dry mixture into the wet ingredients, mixing until just combined.
Fold in Add-Ins: If using chocolate chips or nuts, gently stir them into the batter.
Bake:
Fill the Muffin Tin: Divide the batter evenly among the 12 muffin cups, filling each about ¾ full.
Bake: Place in the oven and bake for 18–20 minutes, or until a toothpick inserted in the center comes out clean.
Cool and Serve:
Let the Muffins Rest: Cool them in the pan for 5 minutes before transferring them to a wire rack.
Enjoy: Serve warm or at room temperature with a cup of coffee or tea.