Heat the oven to 350°F (175°C) and line baking sheets with parchment. Stir together the red velvet cake mix, eggs, and vegetable oil until a thick dough forms, then fold in the white chocolate chips if using.

Drop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between cookies. Bake for 8–10 minutes, until the edges are set while the centers still look slightly soft.

Cool the cookies on the baking sheet for about 5 minutes, then transfer them to a rack to finish cooling. Toss the diced strawberries with the sugar and lemon juice, and let them stand for 10–15 minutes.

Beat the cold heavy cream, confectioners’ sugar, and vanilla extract until medium-stiff peaks form. Break or crumble the cooled cookies into bite-size pieces.

Layer cookie pieces, strawberries, and whipped cream in six glasses, repeating the layers as desired. Finish each parfait with whipped cream and a small strawberry or cookie crumb garnish.