Preheat the oven to 375°F. Line a baking sheet with foil and arrange the saltine crackers in a single layer, making sure they fit snugly together.
Dice the strawberries and pat them dry thoroughly with paper towels. Set aside while you prepare the toffee.
In a saucepan over medium heat, melt the butter and brown sugar together. Once the mixture comes to a boil, stir constantly for 3 minutes.
Pour the hot toffee evenly over the crackers and spread it to cover. Bake for 6–7 minutes, until bubbly and lightly browned.
Sprinkle the semi-sweet chocolate chips over the hot toffee and return the pan to the oven for 1 minute, just until the chocolate softens. Spread into an even layer.
Top with the white chocolate chunks and bake for 1 more minute. Swirl the melted chocolates together with a knife or toothpick.
Sprinkle the strawberries over the warm chocolate, gently pressing them into place.
Freeze for 30 minutes, or until firm. Break into pieces and serve.
Notes
Pat the strawberries completely dry to keep the toffee crisp.
Use dark chocolate for a richer flavor, if desired.
No freezer? Chill in the refrigerator for about 1 hour.
Line the pan with foil or parchment for easy cleanup and removal.
Store leftovers in an airtight container in the refrigerator for up to 4 days.