Use finely ground almond flour: Almond flour that is too coarse can make the cookies feel heavier and less tender.
Measure the flours carefully: Too much flour can make the dough dry, so spoon the flour into the measuring cups and level it off.
Do not overfill the centers: A small spoonful of jam is enough since it can spread a little as the cookies bake.
Press the indent gently: Make the thumbprint deep enough to hold the jam, but not so deep that the cookies crack apart too much.
Let them cool before moving: These gluten-free thumbprint cookies are a little delicate when warm, so they hold together better once they have cooled a bit.