Start by whisking together flour, baking soda, baking powder, salt, and chai spices in a bowl. I like to mix thoroughly so the spices are evenly distributed. This ensures every bite has that warm chai flavor.
In another bowl, beat the softened butter with brown and granulated sugar until light and fluffy. This step is key for soft cookies, so don’t rush it. I usually mix for about 2–3 minutes until it looks creamy.
Add the egg, extra yolk, and vanilla extract to the butter mixture. Mix until everything is smooth and well combined. The extra yolk makes the dough richer and gives a chewy texture.
Gradually add the dry ingredients into the wet mixture. Stir gently until just combined to avoid overmixing. Overmixing can make cookies dense instead of soft.
Gently fold in the white chocolate chips and toffee bits. I like to reserve a few to press on top before baking for a bakery-style look. This step adds texture and bursts of sweetness.
Scoop the dough into balls and place them on a tray. If you have time, chill them for 20–30 minutes for better flavor and thicker cookies. I’ve found chilling really improves the final texture.
Preheat your oven to 350°F (175°C) and bake for 10–12 minutes. The edges should be golden while the centers stay soft. Don’t overbake, as they continue to set after coming out of the oven.