Rinse blackberries and pat dry, then cut each blackberry into halves or thirds, depending on size of berry.
Blend eggs and sugar with mixer for 2 minutes in a large bowl, until mixture has lightened and thickened.
Blend in vanilla extract.
Whisk together almond flour, baking soda, baking power, and salt in another bowl, then stir into liquid ingredients.
Stir in chopped blackberries.
Scoop into lined muffin tin.
Bake for 18-21 minutes, or until a toothpick inserted into the middle of a muffin comes up almost clean. Muffins will be lightly browned on top.
Notes
Best eaten the day you make them, but you can leave out at cool room temperature for 48 hours. You can also keep in an airtight container, but that tends to make the tops a little sticky. We recommend keeping them out of a container for 24 hours, then storing in an airtight container for up to another 2 days. Believe it or not, the almond flour will keep the muffins nice and moist! These muffins will freeze well too. Note that this recipe makes 11 muffins with a lovely dome on top. You can stretch the batter into 12 muffins, but they will be much flatter on top. For that reason, we prefer to pack the muffin cups pretty well with batter and let them rise.Make sure to not pack your almond flour too tightly—use the spoon and level method if you can. Too much almond flour will make the muffins very dense.