1. Prepare the Pudding: In a bowl, whisk together sweetened condensed milk and cold water until smooth. Add the instant vanilla pudding mix and blend until fully combined. Cover and chill for at least 1 hour or until firm.
2. Make the Peach Filling: In a skillet over medium heat, combine peaches, sugar, brown sugar, and lemon juice. Cook for 2 minutes until the sugar starts to dissolve. Stir in cornstarch and continue cooking for about 5 minutes, or until the mixture thickens. Remove from heat and let cool, refrigerating if preferred.
3. Prepare the Crumble Topping: Mix together butter, sugar, brown sugar, flour, and cinnamon until a crumbly texture forms. To avoid raw flour, heat the flour in a microwave-safe bowl in 30-second intervals until warm, about 90 seconds total.
4. Whip the Cream: In a stand mixer, whip the heavy cream until stiff peaks form. Gently fold the chilled pudding mixture into the whipped cream until well combined.
5. Assemble the Dessert: Layer the pudding mixture, Nilla wafers, peach filling, and crumble topping in a trifle bowl or individual serving glasses. Repeat layers as desired and finish with extra whipped cream and crumble topping.
6. Chill and Serve: Cover and refrigerate for 4-6 hours to allow the flavors to meld and the Nilla wafers to soften. Serve chilled and savor!
