1) Preheat the oven to 400°F.
2) Spray muffin cups with cooking spray.
3) In a large bowl, add in margarine and sugar and whip it up with an electric beater to get a creamy mixture.
4) Continue whipping as you add in the eggs, one by one.
5) In a bowl, combine flour, poppy seeds, salt and baking soda.
6) Add the dry ingredients into the whipped mixture, part by part, alternating with small portions of yoghurt.
7) Add in vanilla extract and blend well.
8) Pour the batter into the muffin cups to fill 2/3 of each cup.
9) Bake the muffins for about 15 to 20 minutes.
10) Serve the Poppy Seed Poundcake Muffins as a tea-time snack.