Whisk milk and peanut butter together in a large bowl until fully incorporated. Whisk in 3/4 cup sugar, beaten eggs, vanilla extract, and salt. Add bread cubes and toss to coat. Cover and refrigerate for 20 minutes, stirring once after 10 minutes.
Meanwhile, quarter strawberries and toss with remaining 1/4 cup sugar in a medium bowl. Let sit, stirring occasionally, until ready to use.
Preheat the oven to 350 degrees F (175 degrees C). Spread butter in a 9x13-inch (or 3-quart) baking dish.
Transfer 2/3 of the bread mixture to the prepared dish; spread in an even layer. Dollop 1/2 of the preserves over top in small spoonfuls. Scatter 1/2 of the sliced strawberries and juices over top. Top with remaining bread mixture and remaining strawberries and juices. Cover with foil.
Bake in the preheated oven for 15 minutes. Uncover and continue baking until just set, 35 to 45 minutes longer.
Remove from the oven and immediately spread remaining preserves over top. Let rest for 5 minutes, then sprinkle with peanuts and serve.