Heat oven to 375° F.
Line a standard 12-cup muffin tin with paper liners.
Whisk together the flour, sugar, flax meal, baking soda, and salt in a large bowl.
In a separate bowl, whisk together the bananas, eggs, yogurt, butter, and vanilla extract. Whisk the wet ingredients into the dry ingredients until just combined.
Divide the batter among the prepared muffin cups and top with the almonds.
Bake until a toothpick inserted in the center of a muffin comes out clean, 20 to 25 minutes.
Let cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.