1. Preheat the Oven:
   Preheat your oven to 180°C.
2. Prepare the Squash:
   Peel and cut the squash into small chunks. Steam or boil the squash until tender, about 10-15 minutes. Allow it to cool slightly.
3. Make the Dough:
   Mash the cooked squash until smooth. Combine the squash mash with the whole grain flour in a mixing bowl, forming a dough. If the dough is too dry, add a small amount of water. If too sticky, add a bit more flour.
4. Shape the Fingers:
   On a lightly floured surface, roll the dough out to about 1 cm thickness. Cut the dough into finger-sized shapes, about 5 cm long.
5. Bake the Fingers:
   Place the squash fingers on a baking sheet lined with parchment paper. Bake in the preheated oven for 20-25 minutes, or until they turn a light golden color and firm up.
6. Cool and Serve:
   Let the fingers cool completely on a wire rack before serving them to your baby.

Summary:
This recipe is an excellent lunch option for babies, especially during baby-led weaning. The whole grain flour provides essential fibers and nutrients, while the squash adds a pleasant sweetness and is rich in vitamins A and C, beneficial for a baby's developing immune system.

Storing Options:
Store the cooled squash fingers in an airtight container in the refrigerator for up to 3 days. They can be reheated gently in the oven or served at room temperature. Additionally, you can freeze the baked fingers for up to 1 month; to reheat, thaw and warm them up in the oven.

Possible Side Effects/Allergies:
Always ensure your baby does not have a wheat or gluten allergy since whole grain flour contains gluten. Introduce any new food gradually and watch for signs of allergies, such as rashes, swelling, or gastrointestinal issues.