Preheat the oven to 325˚F (160˚C). Line a baking sheet with parchment paper or a baking mat.
In a small mixing bowl, whisk together 50 g sourdough discard, 50 g maple syrup, 40 g peanut butter, and 1 teaspoon vanilla extract until smooth.
In a medium mixing bowl, stir together 150 g old-fashioned rolled oats, ½ teaspoon ground cinnamon, and ⅛ teaspoon fine sea salt until combined. Pour the wet ingredients over and stir until combined.
Spread out on the baking sheet evenly. Bake for 20-25 minutes until lightly golden brown, stirring halfway through. Leave to cool on the baking sheet for 15-20 minutes, then add 100 g dried strawberries and 50 g chopped peanuts. Cool completely before storing in an airtight container.