Whisk together the sugar, cornstarch, and salt in a heavy saucepan. Slowly whisk in the cold milk until completely smooth. Cook over medium heat, stirring constantly, until the mixture reaches a gentle simmer. Continue cooking for another two to three minutes.

Whisk the egg yolks separately until smooth. Slowly add one cup of the hot milk mixture while whisking continuously to temper the eggs. Return everything to the saucepan.

Cook over medium-low heat, stirring constantly until the custard becomes thick and coats the back of a spoon. Remove from the heat and stir in the butter and vanilla until smooth and glossy. Strain through a fine-mesh sieve into a clean bowl. Cover the surface directly with plastic wrap and refrigerate for at least three hours or overnight.

Meanwhile, combine the sliced strawberries with one tablespoon of the reserved sugar. Let them rest for 15 minutes before draining thoroughly. Slice the bananas just before assembling the Strawberry Crunch Banana Pudding.

Preheat the oven to 350°F (175°C). Grease a 13×9-inch baking dish.

Arrange a layer of vanilla wafers over the bottom of the dish. Spread half of the chilled custard evenly over the cookies. Add half of the banana slices followed by half of the strawberries. Repeat the layers with more wafers, custard, bananas, and strawberries. Finish with a final layer of vanilla wafers.

Mix together the melted butter, brown sugar, granulated sugar, flour, cinnamon, nutmeg, cloves, and chopped nuts until crumbly. Sprinkle evenly over the top layer.

Bake for 30 to 35 minutes until the topping is deeply golden and bubbling around the edges.

Allow the pudding to cool for about 45 minutes before serving warm, or chill for at least two hours for a firmer texture. Refrigerating overnight produces the cleanest slices and richest flavor.