
Toast almonds 10 min, cool. Whisk butter and sugar, then remaining wet ingredients. Stir in dry ingredients with wooden spoon. Shape into 2 logs, bake 25 min at 180°C/350°F (160°C fan). Cool, slice 8mm / 1/3" thick, bake 24 min (flipping halfway) at 150°/300°F (130°C fan), cool on trays.
Preheat the oven to 180°C/350°F (160°C fan-forced).
Toast almonds - Spread the almonds on a tray and bake for 10 minutes, shaking the tray once. Fully cool before adding into dough.
Wet ingredients - Whisk the butter and caster sugar in a bowl. Add eggs, vanilla and almond extract, whisk to combine.
Dry ingredients - Add the flour, then scatter the baking powder and salt across the surface. Mix with a wooden spoon until the flour is almost completely mixed in. Add the almonds, mix until fully combined - it should be like a cookie dough, a bit sticky but just firm enough to handle. (If it's super sticky, refrigerate 15 min).
Logs - Divide the mixture into two and scrape out onto a paper lined tray. Shape into 2 logs 5 cm wide, 2 cm tall, 27 cm long (2 x 0.8 x /12"), set 7cm/2.5" apart - they will spread. (If the mixture is sticky, use wet hands, if really sticky, refrigerate dough for 10 minutes).
Bake 1 (30 minutes) - Bake for 25 minutes or until light golden. Fully cool - about 1 hour. (Cooler = easier to slice without crumbling, it's even easier the next day).
Preheat oven to 150°/300°F (130°C fan-forced).
Slice - Using a sharp serrated knife, slice on the diagonal into 7mm / 1/3" thick slices. You can cut thicker if you want, but I like my biscotti thinner. I get ~40 pieces plus log ends.
Bake 2 (24 minutes) - Place on 2 lined trays. Bake for 12 minutes, flip, then bake for another 12 minutes or until light golden. (They will take longer if you cut yours thicker).
Cool on the tray - they will fully crisp once cool. Enjoy!