I got the recipe off of twopeasandtheirpod.com, not following it fully as I never do and didn't have all the ingredients available..
So what you'll need is:
2/3 cup sugar
Grated zest and juice of one lemon (The lemon I used was too squishy and I wasn't to grate it so no zest for me..)
2 cups of Flour (this I sifted so it's nice and fluffy)
2 teaspoons baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt
3/4 cup sour cream or plain greek yogurt (I used greek yogurt)
2 large eggs (not sure mine were large, then again I do live in Europe and the sizes tend to be smaller here)
1 teaspoon pure vanilla extract
113 grams unsalted butter
2 tablespoons poppy seeds
First off you're meant to mix the sugar with the zest, obviously that didn't work for me so I just mixed all the dry ingredients (sugar, flour, baking soda, baking powder and salt) together in one bowl and all the wet ones (melted butter, vanilla extract, eggs, greek yogurt and lemon juice) in another. WAIT with the POPPY SEEDS!!
Then I added the liquid ingredients to the dry ones and mixed those together, when that was done I added the two spoons of poppy seeds and dished them out into the baking tray (I used cupcake cups as I don't have a baking tray spray thing) then I shoved them into the oven and voila.
The oven I preheated to 200°C and the muffins I put in for 13 minutes..
Twopeasandtheirpod.com also gives and icing recipe, not sure yet if I'll be using it or not but incase you're interested here it is:
1 cup sifted confectioners sugar
2-3 spoons lemon juice
You mix the two together and dribble it onto the muffins.