Whisk together all of the dry ingredients and set aside.
Zest one lemon into your sugar. Rub the zest into the sugar with your fingers to release the lemon oils and add more lemon flavor.
Add eggs, buttermilk, yogurt, melted and cooled butter, oil, and lemon juice to the sugar and whisk to combine. Fold in the poppy seeds and allow to soak in the wet ingredients for 10 minutes.
Add wet to dry and mix until just combined. Don't over mix. Just bring together until all the dry flour disappears. A few lumps are okay.
To make jumbo muffins, use a jumbo muffin tim or use tulip muffin liners in a standard muffin pan. Scoop about ⅓ cup of batter into 8 jumbo cups or liners.
To make 12 standard size muffins, use a medium scoop or measuring cup, and fill each muffin cup ¾ full (about ¼ to ⅓ cup).
Spray the back of a tablespoon with nonstick spray and make a depression on the top of each muffin. Add one tablespoon of lemon curd into each depression.
Bake at 425° for 5 minutes. After 5 minutes turn the oven down to 350°, without opening the oven door. Bake for another 18 to 22 minutes for jumbo muffins and 15 to 18 minutes for standard size muffins, or until a clean toothpick inserted into the muffin comes out with no crumbs attached.
Allow to cool in the muffin pan for 10 minutes and then transfer to a wire rack to cool a bit more before eating. Careful the curd is hot!