Place the softened butter, brown sugar, and granulated cane sugar in the bowl of a stand mixer fitted with the paddle attachment (or use a large bowl and an electric hand mixer).
Cream the butter and sugars on medium-high speed until light and fluffy, scraping down the bowl as needed.
Add the egg and vanilla extract, then beat on medium speed until fully incorporated and the mixture is smooth; scrape the bowl again.
In a separate bowl, whisk together the gluten-free flour, baking powder, baking soda, and sea salt until evenly combined.
With the mixer on low, add the dry ingredients to the wet ingredients and beat until a thick cookie dough forms, stopping to scrape the bowl if needed.
Stir in the white chocolate chips, chopped macadamia nuts, and dried cranberries until evenly distributed through the dough.
Cover the bowl with plastic wrap and refrigerate the dough for 1 hour to firm up.
When ready to bake, preheat the oven to 350°F (175°C) and line a large baking sheet with parchment paper.
Scoop mounds of chilled dough onto the prepared baking sheet, spacing them well to allow for spreading.
Bake on the center rack for 11 to 13 minutes, or until edges are lightly golden; 9–11 minutes yields chewier cookies and 12–13 minutes yields crisper cookies depending on size.
Let the cookies cool on the baking sheet for at least 10 minutes, then transfer to a wire rack to finish cooling.