Preheat oven to 375 degrees F (190 degrees C). Separate the egg whites from the yolks. Add Cream of Tartar to the whites and beat on high until soft peaks are achieved. In another bowl, combine the egg yolks, cooled melted butter, almond meal, baking powder and salt (Adding a teaspoon of sugar substitute to the batter can help reduce the mild egg taste). Mix until combined. This will be a lumpy thick dough until the whites are added. Add 1/3 of the beaten egg whites to the mix. Slowly add the remaining 2/3 of the egg whites and gently mix until fully incorporated. Be careful not to over-mix as this is what gives the bread it's volume! Pour mixture into a buttered 8x4 loaf pan (silicon pan doesn't need any butter). Bake for 30 minutes. Check with a toothpick to ensure the bread is cooked through. Enjoy! One loaf makes approx. 15 slices (I like a thicker slice of bread). Be sure to cut only as needed so it doesn't dry out.