Soft, chewy double chocolate mochi cookies that are crispy on the outside and stretchy on the inside. These easy gluten-free and vegan cookies are stuffed with homemade mochi for the ultimate chewy bite!
In a small bowl, stir together the ground flaxseed and water to make a flaxseed egg. Let sit for 10 to 15 minutes until it develops a gel-like consistency. Meanwhile, in a separate bowl, whisk together the gluten-free plain flour, cacao powder, xanthan gum (if using), baking powder, and baking soda. Set aside.
In a medium bowl, cream the vegan butter and cane sugar using a hand mixer on low speed. Mix until light and fluffy, then add the flaxseed egg and vanilla extract and stir with a spatula. Add the flour mixture and stir to combine.
Wrap the dough in cling film and chill for 15 to 20 minutes until firm.
While the cookie dough is chilling, whisk together the shiratamako and cane sugar in a medium mixing bowl. Pour in the warm water and mix until combined. Steam for 10 minutes over medium heat until the batter becomes solid.
Dust a non-stick work surface generously with cornstarch. Use a scraper to transfer the mochi to the surface. Once cool enough to handle, dust with more cornstarch. Cut into 18 equal portions (5–6 grams each).
Preheat the oven to 180°C (350°F) and line a baking sheet with parchment paper.
Divide the cookie dough into 18 small balls (around 20 grams each).
Flatten each cookie ball and place a mochi ball onto it. Seal the cookie by gathering all sides together. Roll into a ball and press gently into a cookie shape. Press in chocolate chunks or chips.
Bake for 15 to 20 minutes (I baked for 17 minutes). Let cool on the baking sheet for about 10 minutes before transferring to a cooling rack. Serve warm or at room temperature.