Recipe I use:
100g grade AA brown large egg white
200g confectioners sugar
110g almond flour (I grind my almond flour using nutribullet)
5g egg white powder
1/4 teaspoon cream of tartar
I use a kitchen aid to beat the egg white gradually, starting at speed 4, after about 3 mins I added the sugar and egg white powder mixture slowly. I increase the speed to six, beat for another 3 mins, then increase to 8 for another 2 mins, and speed 10 for 1mins. So the total beating time is about 9 mins.
Then I fold in the almond flour and confectioners sugar mixture(sifted) gradually. When it's ready, I pipe them in a size about 1.25 inch space in-between 3 quarters to 1 inch. Then I let them rest for about 30 mins until the surface is not sticky. I baked them in a whirlpool conventional oven for about 11 mins at temperature 285 Fahrenheit. They came out looking like the picture below. Please help! What did I do wrong?