Put rinsed berries and sugar into a saucepan and stir to combine.

Heat on medium to medium high (stirring almost constantly) until the berries start to break down and release their juice. If necessary, add a small splash of water to get the process going.

When the mixture comes to a boil, lower the heat and simmer until the berries have broken down almost completely into a saucy consistency. You can help them along by smashing them with the back of your spoon. Note: you can strain your sauce to remove seeds at this point, but I don’t bother.

Make a slurry of the cornstarch and a little water, mixing until smooth, and stir it into the sauce.

Bring back to the boil and cook gently for a minute or two more, until the sauce has thickened. Note: It will continue to thicken as it cools.

Let cool to room temperature before using.

Preheat oven to 350F. Lightly spray a 9x13 baking pan.

Put the flours, sugar, baking powder and salt in a food processor and pulse to combine.

Add the cold butter (cut in pieces), egg, and almond extract to the bowl. Pulse until the mixture becomes crumbly, then pulse/process until the dough just starts coming together, but it will still be crumbly.

Put ⅔ of the dough in the bottom of the prepared pan. I like to scatter it all over the surface and then gently pat down with the back of a measuring cup, finishing with an offset spatula to smooth. Get it even, but don't compact it down super hard.

Spread a thick layer of jam over the top of the crust. Note: you may not need all of the jam, use the rest on toast!

Sprinkle the rest of the dough over the jam. Follow with the sliced almonds.

Sprinkle 1 teaspoon sugar evenly over the top. Bake for 30 minutes, or until just starting to turn golden around the edges.