Preheat oven to 350℉ and line a muffin tin with paper liners.
In a large bowl, whisk together flour, baking powder, baking soda, salt, and sugar. Set aside.
In a separate bowl, cream together butter and eggs. Add almond extract, vanilla extract, lemon zest and buttermilk.
Add the wet ingredients to the dry ingredients and mix until just combined. Fold in poppy seeds until evenly distributed.
Fill each muffin tin about ¾ of the way full. Top each muffin with a sprinkle of sliced almonds (optional).
Bake for 15-18 minutes, until muffins are slightly golden on top or toothpick inserted into the center of a muffin comes out clean with a few crumbles. Transfer muffins to a wire rack and let cool before serving.
Notes
Fill muffin tins at least ¾ of the way full. These are regular size (not jumbo) muffins, but we still want that bakery-style fullness.