Sift flour into a bowl and ½ tsp baking powder. Season with salt and pepper. Using a fork, whisk milk and eggs together in a jug until combined. Pour over flour. Stir until smooth. Add corn and zucchini. Stir until well combined.
Add enough oil to a large, non-stick frying pan to cover base. Heat over medium heat until hot. Using 1/4 cup of mixture per fritter, spoon mixture, 3 fritters at a time, into pan. Cook for 3 to 4 minutes each side or until golden and firm to touch in the centre. Transfer to a wire rack to cool.