Preheat oven to 350°F/180°C.
Line (or grease and flour) a muffin pan.Whisk together in a medium bowl almond flour, flaxseed meal, psyllium husk, poppy seeds, baking powder, and salt.
Set aside.
If using butter: cream butter in a large bowl until softened (1 minute), add the sweetener of choice and continue to cream until light and fluffy.
Mix in lemon zest, vinegar, and vanilla extract until fully incorporated.
Mix in the eggs one at a time, the batter will appear slightly 'broken' (don't worry!).
If using coconut oil or ghee: beat melted and cooled coconut oil or ghee with eggs and sweetener until fully incorporated.
Mix in lemon zest, vinegar, and vanilla extract until fully incorporated.
Add in the dry flour mixture in two parts, alternating with the lemon juice and sour (or coconut) cream.
Mix for 2 to 3 minutes until fully incorporated and elastic, the batter will thicken as you mix.
Distribute batter evenly into muffin pan, smoothing out the tops with wet fingertips.
Bake for 15 to 18 minutes, until lightly golden and a toothpick inserted comes out clean.
Check in on them after minute 10, and cover with aluminum foil as soon as they begin to brown (minute 14 for us).
Allow to cool for 15 minutes in the pan before removing, and cool completely in a rack before glazing.While the muffins are cooling, make the lemon glaze by mixing the powdered sweetener with the lemon zest and juice.
Adding lemon juice as needed until desired consistency is reached.
Drizzle over muffins.
Store in an airtight container for up to 3 days, though we're fairly certain they'll be long gone before then.