In a large bowl, whisk together the melted butter, brown sugar, sugar, tahini, honey, and vanilla extract until smooth. Add the egg and whisk to combine.

In a medium bowl, stir together the sorghum flour, tapioca starch, salt, baking powder, and baking soda. Add the dry ingredients into the butter mixture and stir to combine. Stir in the chopped macadamia nuts. The dough will be quite runny at this point. Cover the bowl with plastic wrap and chill for at least 4 hours, preferably overnight.

Preheat oven to 375°F (190 °C). Place oven rack in middle. Line a sheet pan with parchment paper. Add sesame seeds to a medium bowl.

Using a 3-tablespoon ice cream scooper, scoop 6 balls of dough. Roll them in sesame seeds and place them on prepared baking sheet leaving 3 inches (8 cm) in between. The cookies spread a lot so it is important to leave enough space in between.

Bake the cookies for 9 to 10 minutes or until the edges are dark brown and center still feels slightly underbaked. As soon as they come out of the oven, round them using a large cookie cutter. Place it over the cookies and swirl around so the cookie cutter brings in the cookie edges and creates a perfectly round cookie with some ripples. You must do this while cookies are still warm. Let the cookies cool in the pan for 5 minutes. Repeat with remaining cookie dough.

Store cookies in an airtight container, at room temperature, for up to 3 days.