To keep gluten-free thumbprint cookies from cracking, you can follow these tips and techniques:

1. Use the Right Gluten-Free Flour Blend: When baking gluten-free thumbprint cookies, it's crucial to use a high-quality gluten-free flour blend that is specifically designed for baking. Look for a blend that contains a mix of flours like rice flour, tapioca flour, and potato starch to help create a tender and flexible dough.

2. Add Xanthan Gum: Xanthan gum is a common gluten substitute in gluten-free baking. It helps to bind the ingredients together and improve the texture of the dough. If your gluten-free flour blend doesn't contain xanthan gum, consider adding 1/4 to 1/2 teaspoon per cup of flour to the recipe.

3. Avoid Overmixing: When combining the ingredients, be careful not to overmix the dough. Overmixing can lead to a tougher texture, making the dough more prone to cracking.

4. Chill the Dough: After forming the cookie dough balls, refrigerate them for at least 30 minutes before making the thumbprint indentation. Chilled dough is less likely to crack during this step.

5. Proper Thumbprint Technique: Gently press your thumb or the back of a rounded spoon into the center of each cookie to create the indentation. Avoid pressing too hard, as this can cause the edges to crack.

6. Check for Cracks: Before baking, inspect the edges of the thumbprint cookies. If you notice any cracks, use your fingers to gently smooth them out to maintain the cookie's shape while baking.

7. Fill the Thumbprint Gently: When adding the filling (such as raspberry jam), do so carefully and avoid pressing down too forcefully. A gentle touch will help the filling stay in place and prevent cracking.

8. Bake at the Right Temperature: Ensure your oven is properly preheated and maintains the correct temperature throughout the baking process. Rapid temperature fluctuations can cause cookies to crack.

It is best to freeze Raspberry Almond Thumbprint Cookies after baking and cooling. Once the cookies are baked, allow them to cool completely at room temperature. Then, arrange the cooled cookies in a single layer on a parchment paper-lined baking sheet and place them in the freezer for about 1 to 2 hours, or until they become firm. Once frozen, transfer the cookies to a freezer-safe container or resealable bag, ensuring to remove any excess air before sealing. By freezing the baked cookies, you can maintain their texture and flavour, making them a convenient and delightful treat to enjoy at a later time.