Preheat your oven to 350 degrees Fahrenheit. While the oven warms up, grab an 8-inch square pan and line it with aluminum foil. This makes for easy removal later! Spray the foil with cooking spray to prevent any sticking.
In a large mixing bowl, whisk together 1 cup of flour, ¾ cup of sugar, 2 teaspoons of baking powder, ½ teaspoon of cinnamon, and a pinch of salt. This dry mixture will be the base of your cake, so make sure to combine everything well.
In a separate smaller bowl, whisk together your wet ingredients: 1 large egg, ½ cup of buttermilk, ⅓ cup of Greek yogurt, 3 tablespoons of oil, and 1 teaspoon of vanilla extract. This mixture brings moisture and richness to the cake.
Now, add the wet mixture to the dry ingredients. Use a spatula or spoon to mix lightly until just combined. It’s okay if it’s a bit lumpy; you don’t want to overmix here!
In another small bowl, toss the strawberries with 1 tablespoon of flour. This helps keep them suspended in the batter instead of sinking to the bottom as it bakes.
Gently fold the floured strawberries into the batter. If you’re using frozen berries, there’s no need to thaw them! Just add them straight to the mix. For fresh berries, be aware that they will release less moisture, so adjust your baking time accordingly.
Turn the batter out into your prepared pan and spread it evenly. Now it’s time to melt the peanut butter! Place it in a small microwave-safe bowl and heat it for about 30 seconds until melted.
Drizzle the melted peanut butter over the top of the cake batter. Using a toothpick or a skewer, gently swirl the peanut butter into the batter. Don’t overdo it; you want to see some lovely swirls!
Place the pan in the preheated oven and bake. I suggest keeping an eye on it, especially after 40 minutes. You’re looking for the center to be slightly domed and golden, with a toothpick inserted coming out clean or with a few moist crumbs.
Once baked to perfection, remove the cake from the oven and place it on a wire rack to cool for at least 30 minutes. This cooling step is crucial for the cake to set properly. Optionally, you can drizzle more peanut butter over the top or serve it with a glaze if you’re feeling fancy!
