Prep your pan and oven. Preheat the oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease with coconut oil or butter.

Mix the dry ingredients. In a large bowl, whisk almond flour, coconut flour, baking powder, salt, and granular sweetener until no lumps remain.

Blend the wet ingredients. In another bowl, whisk peanut butter, eggs, almond milk, melted butter (slightly cooled), vanilla, and apple cider vinegar until smooth.

Combine wet and dry. Pour the wet mixture into the dry. Stir with a spatula just until combined. If using liquid stevia or monk fruit drops, add now. The batter will be thick but scoopable.

Fold in chocolate chips. Gently fold 1/2–3/4 cup sugar-free chocolate chips into the batter, reserving a spoonful for the tops if you like.

Fill the tins. Divide the batter evenly among the 12 muffin cups. Sprinkle with extra chocolate chips or a pinch of flaky sea salt for a sweet-salty finish.

Bake. Bake for 18–22 minutes, or until the tops are set and a toothpick inserted in the center comes out mostly clean with a few moist crumbs.

Cool. Let muffins cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. This helps them set and keeps the texture tender.

Enjoy. Serve warm or at room temperature. They’re excellent with coffee or a cold glass of unsweetened almond milk.