Preheat oven to 350 degrees. Lightly grease a muffin tin.
Sift flour baking powder and salt together. (Don't skip the sifting - it will make for extra soft, fluffy muffins.) Gently stir sugar into flour mixture. In a separate bowl, combine remaining ingredients (through lemon juice) and whisk to combine. Gently, fold wet ingredients into dry ingredients just until combined (don't over-mix).
Spoon batter evenly into 10 spaces in the muffin tin. Bake just until tops begin to turn golden, 20-25 minutes. Allow to cool on a wire rack.
If desired, whisk together powdered sugar, lemon juice and zest to create a glaze. Drizzle over muffins before serving