Preheat oven to 400 degrees F. Generously grease a 9-inch round cake pan and set aside.

In a large bowl, beat softened butter and sugar together with a hand mixer or stand mixer at medium-high speed until light and fluffy, 2-3 minutes. This will take longer than you think it should - keep going until it's quite pale in color.

Beat in the egg at medium speed until fully combined, then beat in almond extract and lemon zest.

In a separate small bowl, whisk together flour, baking powder, baking soda, and salt. Add a third of the flour mixture to the batter, and mix at low speed until just combined. Pour in about a third of the buttermilk, then mix at low speed again until just combined. Continue alternating the rest of the flour and buttermilk. Mix just until combined each time - don't overmix. The batter will be quite thick.

Scoop the batter into the cake pan, and spread it out evenly. It will seem a rather thin cake layer, but don't worry, it will puff up in the oven. Arrange the berries evenly scattered over top of the batter. Sprinkle the 1 ½ tablespoons of granulated sugar over top. Don't skip this step - it produces a lovely crunch when baked!

Bake until cake is golden brown on top and a toothpick inserted in the center comes out clean, 22-25 minutes. Mine needed 25 - watch carefully, as my toothpick came out wet at 23 minutes but clean at 25!

Cool for 20 minutes in pan, then run a knife along the edges and invert onto a cooling rack or plate to cool completely. Note you'll actually have to invert it 2 times - once upside-down onto a rack, and then back upright again onto another rack or plate.

Serve cooled cake dusted with powdered sugar or topped with whipped cream!