How to Make It
Whisk flour, sugar, baking powder, and salt together in a large bowl.
Whisk together milk, eggs, zest, lime juice, and vanilla extract in a separate bowl. Stir in seltzer. Add the wet mixture to the dry mixture, stirring until just incorporated. Gently stir in melted butter; let stand 5 minutes.
Pour ¼ cup of batter per pancake onto a hot, lightly-greased, non-stick griddle and cook 3 to 4 minutes per side. Top pancakes with coconut, graham cracker crumbs, whipped cream, and maple syrup, if desired. Serve immediately.