In a large bowl, whisk together the water and vanilla instant pudding mix until smooth. Add the sweetened condensed milk and continue mixing until fully combined. Cover and refrigerate for at least 4 hours so it thickens properly.
Preheat your oven to 350°F. Hull and chop the strawberries, then toss them with sugar. Spread them on a lined baking sheet and roast until soft and juicy, about 15–25 minutes.
Pour the heavy cream into a chilled bowl. Whip until soft peaks form using a mixer or whisk.
Gently fold the whipped cream into the chilled pudding mixture.
Start with a layer of pudding mixture in your serving dish. Add roasted strawberries and sprinkle crushed vanilla wafers. Repeat layers until all ingredients are used, then chill before serving.