In a bowl mix white and buckwheat flour Add refreshed active starter and milk Mix to a smooth batter Cover and leave in a warm spot until fine bubbles start to appear Add salt and eggs, mixing lightly through the batter Leave a further one to two hours or overnight in the fridge Heat the poffertjes pan well on medium heat Pour the batter into a squeeze bottle or a jug Grease the pan with a little butter then pour the pancake batter into each indentation to the rim Bake the poffertjes for a few minutes until bubbles appear on the top Using a toothpick, bamboo skewer or a fork, flip the pancakes on the other side and bake a further minute or two Repeat with the remaining batter Serve warm dusted with icing sugar and melted butter, maple syrup, fruit or toppings of your choice.