Preheat the oven to 350° Fahrenheit. Line a large baking sheet with parchment paper. Set aside.
Make the masala chai spice by mixing the ginger, cinnamon, cardamom, cloves, and black pepper in a small bowl or jar. Mix together and set aside.
In a large bowl or stand mixer fitted with a paddle attachment, beat together the butter, brown sugar, and white sugar until the mixture is light and creamy. Add the egg and vanilla extract and continue beating until incorporated, scraping down the sides as needed.
Add the oat flour, gluten-free flour, chai spice blend, baking soda, baking powder, and salt to the bowl. Mix until just combined.
Add the chocolate chunks and mix until they’re evenly distributed.
Using a 1-2 tablespoon scoop, scoop the dough onto a parchment-lined baking sheet. Leave a couple inches between each cookie.
Bake at 350° Fahrenheit for 12-14 minutes, until the edges are just starting to turn golden.
Remove from the oven and let cool on the baking sheet for 5-10 minutes before transferring to a cooling rack. Allow to cool completely before serving.
Repeat with remaining cookie dough.
Store cookies in a lidded container at room temperature for up to 5 days. You can also freeze the baked cookies for up to 6 months.
Remaining masala chai spice blend can be stored in an airtight container in the pantry for up to 12 months.