Preheat waffle iron according to manufacturer’s instructions.
Using a fine-mesh sieve sift flour and baking powder onto a sheet of non-stick baking paper. Sift again into a bowl; whisk to well combine.
In bowl of electric stand mixer fitted with paddle attachment beat eggs and sugar until quite pale at medium-high speed, 6 to 8 minutes.
Add vegetable oil and butter; continue beating on medium-high, 2 minutes.
Add vanilla and beat just to combine.
Reduce mixer speed to low, gradually add flour and beat to just combine. Do not over-mix!
Fold in chocolate chips with a large spatula.
Lightly coat waffle iron with vegetable spray.
Pour batter (enough to just cover waffle grid) onto hot waffle iron. Close and bake following manufacturer’s instructions until golden, 2 to 3 minutes.
Garnish with chocolate chips, and chocolate syrup.