Prepare the Pineapple Sauce : In a small saucepan, combine pineapple chunks, sugar, water, and lemon juice. Cook over medium heat for 5–7 minutes until the pineapple softens and the sauce thickens slightly. Mash lightly for a smoother sauce or leave chunks for texture. Remove from heat and set aside.
Prepare the Pancakes : In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt. In another bowl, mix milk, egg, melted butter, and vanilla extract. Fold wet ingredients into dry ingredients until just combined. Gently fold in shredded coconut. Do not overmix.
Cook the Pancakes : Heat a non-stick skillet or griddle over medium heat and lightly grease with butter or oil. Pour ¼ cup batter onto the skillet for each pancake. Cook 2–3 minutes until bubbles form on the surface and edges set, then flip and cook for another 1–2 minutes until golden brown. Repeat with remaining batter.
Serve : Stack pancakes on plates and spoon pineapple sauce generously over the top. Garnish with toasted coconut flakes, fresh pineapple slices, or whipped cream if desired. Serve warm.