Whisk together the flour, baking powder, salt and sugar. In a separate bowl or measuring jug, whisk the melted butter, milk and egg together.
Pour the wet ingredients into the bowl with the dry ingredients then mix until just combined. Fold the grated zucchini, cheese, chives and chilli into the batter.
Line a 12-hole muffin pan with cupcake liners. Fill each cup with the batter.
Place the pan into the oven and allow to bake for 15 minutes or until they are golden brown and a skewer inserted comes out clean.
Remove from the oven and allow to cool to room temperature before serving.