Place lemon juice and milk together into a glass measuring cup or bowl and let sit while you prepare the pancake batter. Milk may curdle, but that’s fine.
Into a large bowl, mix together flour, poppy seeds, baking powder, baking soda, salt, and lemon zest until well combined. Add sweetener, melted butter/oil, egg, vanilla, and milk/lemon juice mixture. Stir just until incorporated—don’t over mix. Depending on the flour you use, a splash more milk may be needed if the batter is too thick. Let batter rest for 2-3 minutes.
Place a griddle or large pan on the stove over medium heat. Melt extra butter or oil in the pan to keep the pancakes from sticking.
When the pan is hot, scoop batter onto griddle leaving 1-2 inches between pancakes. Flip when edges are set. Makes about 6-8 pancakes.
Place 2 cups of blueberries into a large saucepan and stir in orange juice and maple syrup. Bring to a simmer over medium-high heat and add tapioca flour. Use less tapioca flour for a thinner sauce, more for thicker sauce.
Continue to stir until sauce has thickened. Add more sweetener, if needed. Can also add more orange juice or water, if mixture gets too thick. Serve sauce warm over pancakes.