1. Preheat your oven to 350°F (175°C) using the convection setting if you have it.

2. In a medium bowl, combine softened butter, granulated sugar, coconut flour, all-purpose flour and a pinch of salt until smooth.

3. Spread half of the coconut flakes evenly across the bottom of a 9-inch (23 cm) springform pan.

4. Arrange the frozen mixed berries over the coconut layer, leaving about 1 inch (2.5 cm) of space around the edges.

5. Scatter the remaining coconut flakes over the berries, making sure the surface is fully covered.

6. Drop small bits of the butter mixture over the top, using your fingers or a spatula to spread it gently into an even layer.

7. Place the pan on the middle rack of the oven and bake for 25 to 30 minutes, until the coconut is golden and the fruit filling is bubbling. If the top browns too quickly, cover loosely with aluminum foil halfway through baking.

8. Carefully remove the pie from the oven using oven mitts and let it rest for 10 minutes.

9. Serve warm with vanilla ice cream or whipped cream if desired. Be careful when cutting and serving the pie, as the filling may be hot.