Stir together baking mix, poppy seeds, and lemon zest. Whisk together club soda, egg, and butter in a small bowl; gently whisk egg mixture into poppy seed mixture. (Mixture will be lumpy.) Let stand 3 minutes.
Pour about 1/4 cup batter for each pancake onto a hot, lightly greased griddle or large nonstick skillet. Cook pancakes 3 to 4 minutes or until tops are covered with bubbles and edges look dry and cooked; turn and cook other side. Serve with Blackberry Maple Syrup and, if desired, crème fraîche. Garnish, if desired.