Preheat your oven to 350°F (175°C) and lightly grease a 9-inch round baking dish.
In a large mixing bowl, combine the Greek yogurt, honey, vanilla extract, and eggs. Whisk until smooth and well combined.
Add the rolled oats, salt, cinnamon, and lemon juice to the yogurt mixture. Stir until everything is evenly mixed.
Gently fold in the mixed berries, being careful not to break them apart if using fresh berries.
Pour the mixture into the prepared baking dish and spread it evenly.
Bake in the preheated oven for 30-35 minutes, or until the top is set and lightly golden.
Remove from the oven and let it cool for about 10 minutes before slicing and serving.