Make the shortbread. Grease a 9x5 inch loaf tin and line it with non-stick baking paper, leaving a little overhang for easy removal.
In a mixing bowl, combine the flour, sugar and salt (if using). Add the vanilla, then the cubed butter and rub it into the flour till all the flour is moistened. Bring it together with your hands and it will form a soft dough.
Press the dough into the prepared tin, using your fingertips to spread it evenly and firmly into the pan. You can also use the bottom of a measuring cup to help spread it. Once done, place the tin in the fridge for 10 minutes. Preheat the oven to 175 C.
Bake the shortbread base for 10 to 12 minutes until barely browned. Keep the oven on at 175 C.
Make the almond frangipane. Beat the butter and sugar with a hand mixer on low speed until light and creamy. Add the ground almonds and vanilla and beat briefly to combine. Finally, beat in the egg, followed by the flour. The frangipane might look a little soft at this stage since the butter would have warmed up especially on hot days. Refrigerate for 15 minutes until thickened but spreadable.
Spread it all over the cooled base, followed by the strawberries in a single layer. Fill the gaps with smaller strawberry slices as needed so that you have lots of berry bites! (see photos below)
Bake for 40 to 45 minutes until the frangipane is golden-brown and the strawberries look roasted and jammy. Let the bars cool in the tin for about 20 minutes, then lift out using the paper overhang and let cool completely. Slice into 8 pieces with a sharp knife and dig in!
These bars are best stored in the fridge because the moisture from the strawberries mean they won't keep very long at room temperature. They taste great fresh of course, but even better cold from the fridge when the frangipane takes on a fudgier texture. Keep them chilled in an airtight tin for 4 to 5 days. Happy baking!