Ingredients:
70 grams butter
1 cup (250 ml) water 
1/4 teaspoon vanilla extract
1 cup of sifted plain flour,
2 eggs, whisked
1 additional egg yolk
Cream Filling
300 ml bottle cream
1 Tbsp icing sugar
Icing
1/3 cup dark chocolate chips or milk chocolate chips
METHOD: 
Pre-heat oven to 190 C.
In a saucepan, heat water and butter until butter melts and mixture begins to boil. Remove from heat.
Stir in sifted flour (adding flour all at once) and mix in briskly using a wooden spoon.
Return to heat for 30 seconds, continuously stirring. Remove from heat and stir in vanilla extract.
Transfer mixture to a bowl and leave to cool for 10 mins.
Beat in egg yolk and then each egg, one at a time until combined. You can use a wooden spoon or slow speed stand-mixer.
Using a piping bag and a 2cm star nozzle pipe the mixture 6 x 13 cm long onto a greased lined baking tray. Make each end of the eclairs a little fuller.
Bake for 25 mins. Remove from oven (leaving oven on) and allow to cool for 10 minutes.
Using a bread knife, cut eclairs in half horizontally, leaving one long edge intact. Return to oven for 3 minutes, then remove and allow eclairs to cool completely on a cooling rack.
Cream Filling
Whip cream and icing sugar together until stiff peaks form.
Using a piping bag and nozzle fill each eclair with cream. Place each eclair back onto the tray and place into fridge.
When cooled, melt down chocolate and drizzle over the eclairs.