Preheat the oven to 350°F. Line two 8x8-inch cake pans with parchment paper, leaving an overhang for easy removal.
In a large bowl, use a spatula or wooden spoon to combine the soft butter and sugar until no butter clumps remain and the mixture is smooth. Add the almond extract and vanilla extract and mix to combine. Alternately, use an electric hand mixer or stand mixer with the paddle attachment and mix on low.
Add the dry ingredients, including the flour, cornstarch, and salt to the butter mixture and stir until the dough starts to come together and pulls away from the sides of the bowl. You may need to mix with your hands to combine. The dough should hold together in a ball, but be slightly crumbly.
Divide the dough in half and press each half into the bottom of the prepared baking pans. Do your best to form the dough into an even flat layer. Bake in the preheated oven for 24-26 minutes, or until the edges are golden brown. If the cookies are browning too quickly, cover them with foil and continue baking until baked through.
Remove the shortbread cookies from the oven and allow them to cool for 10 minutes. Carefully lift the cookies out of the pan with the parchment paper. The cookies are very delicate so if they look like they’re starting to bread while you take them out of the pan, stop and place a cooling rack on top and carefully flip them over onto the rack as a secondary option.
Use a sharp knife to slice the shortbread cookies into 8 or 12 triangles.
Melt the chocolate in 30-second increments in the microwave until smooth. Dip the larger ends of the cookies into the chocolate and let them set on parchment paper. You can top the chocolate with chopped almonds or sea salt while it’s still wet.
Store in an airtight container for up to 3 days. Baked cookies (with or without chocolate) freeze well for up to 3 months. Thaw in the fridge and enjoy.