In a large bowl, whisk egg and add water and milk. Add in butter then flour mixture. Mix well. Pour batter into a glass with spout. Set aside.
Mix canarium nut with chocolate spread. Shape into balls half the size of a marble. Set aside.
Heat a poffertjes mould on medium heat while basting its surface with margarine.
Once hot, pour in batter to fill half the mould. Place chocolate canarium nut filling and cover with the batter again. Close the mould and tip over, and heat for 30 seconds. Repeat until both sides are slight brown (3-4 minutes).
Remove from mould, cut its sides and place on cooling rack. Serve.