Preheat oven to 375 degrees F (190 degrees C). Grease 12 muffin cups.
Combine flour, sugar, stevia, baking powder, and salt together in a bowl. Whisk sour cream, butter, and eggs together in a separate bowl; stir into flour mixture just until batter is moistened. Fold coconut and chocolate chips into batter. Fill the prepared muffin cups 2/3-full with batter and top with sliced almonds.
Bake in the preheated oven until a toothpick inserted in the center comes out clean, 18 to 20 minutes. Cool muffins for 5 minutes in the tin before transferring to a wire rack.
