Step 1Heat the oven to 400 degrees. Combine the flour, 1 cup sugar, the baking soda and salt in a large mixing bowl. Set aside.
Step 2Cut two lemons into 1-inch pieces. Put them in a blender and pulse until the lemon is finely chopped. In a small bowl, lightly beat the eggs. Add the milk, butter and chopped lemon. Stir.
Step 3Make a well in the center of the dry ingredients and pour in the lemon mixture. Stir just until all ingredients are moistened.
Step 4Spoon the batter into well-buttered cups of muffin pans, filling each half full.
Step 5Combine the remaining 2 tablespoons sugar and the cinnamon. Sprinkle about one-fourth teaspoon over each muffin. Cut the remaining lemon into 9 paper-thin slices; cut each slice in half. Top each muffin with half a slice of lemon.
Step 6Bake about 20 minutes, until golden brown. Run a small spatula or knife around each of the muffins to loosen, remove from the pan and cool on a wire rack. Serve warm.