Toast the Topping: Adjust an oven rack to the middle position. Preheat oven to 325°F (165°C). Spread the chopped pecans on a small baking sheet and toast until fragrant and slightly deepened in color, about 6–8 minutes. Remove and set aside to cool.
Prepare the Foundation: Increase the oven temperature to 375°F (190°C). Line 16 muffin cups with paper or silicone liners.
Create the Wet Base: In a large glass bowl, vigorously whisk the almond butter and Greek yogurt until the mixture is uniform and creamy. Add the eggs one at a time, whisking well after each addition. Beat in the mashed bananas, maple syrup, coconut sugar, and vanilla extract until fully combined.
Integrate the Dry Mix: Position a fine-mesh sieve over the bowl containing the wet ingredients. Add the all-purpose flour, whole wheat flour, baking powder, baking soda, cardamom, nutmeg, and sea salt to the sieve. Sift the dry ingredients directly onto the wet base.
Finalize the Batter: Using a silicone spatula, gently fold the dry ingredients into the wet until they are about 80% incorporated. Be careful not to overmix; a few streaks of flour are acceptable. Let the batter rest at room temperature for 10 minutes to allow the flour to hydrate.
Portion & Bake: Divide the batter evenly among the 16 prepared muffin cups; each will be about three-quarters full. Sprinkle the toasted pecans generously over the top of each muffin. Bake for 16–20 minutes, or until the tops are golden-brown and a wooden skewer inserted into the center of a muffin comes out clean.
Cool & Serve: Transfer the muffin pan to a wire rack and let the muffins cool in the pan for 10 minutes. Afterwards, you can remove them from the pan to cool completely or enjoy them while they are still warm.