Preheat oven to 350 degrees F. Lightly grease or place paper muffin liners in a 12-count muffin pan.
In a 1 cup measuring cup or small bowl, warm the milk to 80 F. Add the poppy seeds to the milk. Let cool until just slightly warm.
In a medium bowl, mix together the gluten free flour mix, almond flour, baking powder, xanthan gum, and salt. Set aside.
In the bowl of a stand mixer, beat the butter until well blended. Add the Swerve brown sugar and beat until light and fluffy, about 3 minutes. Add in the eggs, one at a time. Beating well after each addition.
Start combining ingredients… Starting with the dry ingredients – add 2 heaping spoonfuls of the dry ingredients to the mixing bowl and mix until blended.
Add 1/3 of the milk-poppy seeds and mix again. Add another 2 heaping spoonfuls of dry ingredients and mix again. Continue alternating with the milk-poppy seed mixture until fully mixed.
After those are mixed in, stir in the vanilla extract and lemon zest.
Spoon the batter into the prepared pan.
Bake for 20 minutes or until they test done with the toothpick test; the top should spring back when pressed gently.
Cream the butter and sugar first before adding the eggs.
Alternate the milk-poppy seed mixture with the flour mixture.
Portion each muffin cup with batter.
Recipe is dairy free and refined sugar free as written, but can be made with dairy and sugar with no other modifications.