Preheat your oven to 350°F (175°C). In a medium bowl, whisk together the all-purpose flour, bread flour, baking soda, and salt until well combined.

In a separate large bowl, beat the softened butter with granulated and brown sugars using a hand mixer until light and fluffy, about 2-3 minutes. Mix in the eggs and vanilla extract until fully incorporated.

Gradually add the dry ingredients to the wet mixture, stirring until just combined to create the perfect salted brown sugar cookie dough.

Line two baking sheets with parchment paper. Using a cookie scoop or tablespoon, drop rounded balls of cookie dough onto the sheets, spacing them about 2 inches apart. Bake in the preheated oven for 8-10 minutes until the edges are barely golden and the centers are still soft.

Remove from the oven and immediately sprinkle coarse salt on top of the warm cookies. Allow them to cool on the baking sheets for a few minutes before transferring to wire racks to cool completely.

While the cookies cool, prepare the butterscotch ice cream. In a large mixing bowl, whip the heavy cream using an electric mixer until stiff peaks form, roughly 4-5 minutes.

In another bowl, combine the sweetened condensed milk, vanilla extract, and salt. Gently fold the whipped cream into the condensed milk mixture until thoroughly combined.

Melt the butterscotch chips carefully in the microwave in 15-second intervals, stirring until smooth, then fold them into the ice cream mixture.

Line a square or rectangular cake pan with plastic wrap for easy removal. Pour the butterscotch ice cream mixture into the prepared pan, spreading it evenly with a spatula. Cover tightly with plastic wrap and freeze for about 2 hours or until the ice cream is firm enough to scoop.

Once the cookies and ice cream are ready, it’s time to assemble your sandwiches! Remove the frozen ice cream from the pan by lifting it out using the plastic wrap.

Use a round cookie cutter to cut out perfect rounds of ice cream. Place a round of ice cream between two cooled cookies, pressing lightly to adhere them together.

Repeat until all cookies and ice cream rounds are used, creating delicious salted brown sugar butterscotch ice cream sandwiches.

Wrap each ice cream sandwich individually in plastic wrap or place them in zipper bags to prevent freezer burn. Return them to the freezer for at least 30 minutes to firm up further.

Serve them straight from the freezer and enjoy!