In a large bowl or stand mixer, beat together the softened butter, brown sugar, and granulated sugar until light and fluffy.

Add the eggs and vanilla extract and mix until smooth.

Add the baking soda and salt and mix briefly.

Gradually add the flour and cinnamon, mixing just until a cohesive dough forms. Fold in the white chocolate chips and toffee bits. The dough should be soft and play-dough-like, not sticky. If needed, add additional flour ¼ cup (30 g) at a time until the desired consistency is reached.

Using a digital scale, portion the dough into 3.5 oz (100 g) balls. Place the dough balls in an airtight container and chill for 24–48 hours.

When ready to bake, preheat the oven to 350°F (175°C) and line baking sheets with parchment paper. Arrange chilled dough balls about 3 inches (7.5 cm) apart.

While the cookies bake, prepare the topping by combining the granulated sugar and cinnamon in a shallow dish.

Bake for 18–20 minutes, until the edges are lightly golden. Cookies will continue to set as they cool.

About 5 minutes after removing from the oven, while cookies are still warm and soft, gently place each cookie face-down into the cinnamon-sugar topping, pressing lightly to coat. Handle carefully, as cookies will be delicate.

Return coated cookies to the baking sheet and allow them to rest for another 10 minutes, then transfer to a wire rack to cool completely.

Store cooled cookies in an airtight container at room temperature for up to 1 week, or freeze for up to 3 months.