Preheat oven to 350F. Line a 9x13 baking pan with parchment paper. Set aside. In a large bowl, beat butter and sugar until smooth. Add egg and vanilla. Gently fold in flour, baking soda, and salt until a smooth dough forms. Stir in chocolate chips.
Spread batter into prepared pan and smooth top. Bake blondies at 350F 20-25 minutes or until top is firm when touched. Cool blondies in pan 10 minutes, then use the foil to remove from pan to a wire cooling rack. Cool blondies completely on cooling rack.
Once blondies are cooled, cut in half down the middle width-wise. Scoop ice cream into 2-in scoops and top the flat side of one of the blondie halves with ice cream. Use an offset spatula to quickly spread ice cream flat. Carefully top ice cream with second blondie half and press firmly to flatten ice cream. Quickly cover with plastic wrap and freeze blondie ice cream sandwiches at least 4 hours or overnight.
Once blondies are frozen, carefully cut into bars and store in freezer until ready to serve. Enjoy!