Preheat the oven to 180°C/350°F degrees.
Put the cold butter in the porcelain 5x8-inch pan and place it in the oven to melt for about 15 minutes.
In a large bowl, whisk together oat flour, baking powder, and salt. Add in honey and milk and whisk until smooth. You can use a hand mixer to speed the process up.
Remove the pan with melted butter from the oven. Slowly pour the batter into the pan. Lastly, evenly distribute diced strawberries into the pan.
Bake for 20-25 minutes or until the toothpick inserted in the center of the cake come out clean.
Let cool for 15 minutes before serving with a scoop of ice cream or a spoon of Greek yogurt.