Spoon the yogurt into a yogurt cheese funnel or a sieve lined with cheesecloth.
Place over a bowl and set aside to drain for 20 minutes.
Transfer to a bowl and fold in the pineapple.
Meanwhile, place the egg whites in a medium bowl and whisk until frothy.
Whisk in the milk and honey.
Add the flour and baking powder; mix well.
Coat a small no-stick frying pan with no-stick spray.
Place over medium heat and allow to warm for a few minutes.
Add about 14 cup batter to the pan and tilt the pan in all directions to spread the batter thinly all over the bottom.
Cook for about 1 minute, or until browned on the underside.
Carefully flip the blintz and brown the other side for about 30 seconds.
Turn the blintz out onto a wire rack.
Repeat until you've used all the batter.
You'll have about 12 blintzes.