Preheat oven to 375° F.
In a large mixing bowl, combine 1 cup sugar, 1/2 cup milk, 1/2 cup oil, 1/2 cup melted butter, 2 large eggs, 2 Tablespoons lemon zest, 1/4 cup lemon juice, 1 teaspoon vanilla extract, 1 teaspoon lemon extract, and 2 Tablespoons poppy seeds. Stir by hand until mixed.
In a separate bowl, combine 2 1/2 cups all purpose flour, 2 teaspoons baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt.
Add the flour mixture to the wet ingredients and stir by hand just until combined.
Gently fold in 1 cup sour cream and stir just until no white streaks remain.
Line 2 muffin tins (24 cups) with paper liners OR spray generously with cooking spray.
Using a cookie scoop or spoon, fill each muffin tin all the way to the top. (This recipe yields 12-14 muffins.)
Bake at 375° for 18 minutes, then check for doneness. *Muffins are done when a toothpick inserted in the center comes out clean. Return to the oven for up to 5 more minutes, just until done.
Remove muffins from the oven and let cool in the pan for 5-10 minutes, then remove from the pan and transfer to a wire rack to cool completely.
Once muffins are cool, make the glaze by combining 1 cup powdered sugar and 3-4 Tablespoons lemon juice in a small shallow bowl. Dip each muffin top into the glaze, then set on a wire rack to dry.