Line a large baking pan with parchment paper or silicone baking mats. Spread 2 cups (1 cup for biscotti and 1 cup for decoration) of almonds on baking pan and toast for 12-15 minutes for whole almonds or 6-8 minutes for slivered almonds, stirring twice during that time. Remove toasted almonds from the oven and turn the oven up to 350F/180°C. Let them cool and pulse into a food processor until coarsely chopped. Set aside.
Prepare a large baking pan with parchment paper or silicone baking mats.
Using a hand mixer or stand mixer fitted with paddle attachment, cream together butter, granulated sugar, and brown sugar until well combined. Add eggs, vanilla extract, almond extract and mix until well combined.
In a separate bowl, toss all purpose flour, baking powder, and salt together. Add dry ingredients to wet ingredients and mix until well incorporated with a spatula.
Stir in half the toasted almonds into the batter and mix until well combined.
Divide the dough in half and them into two logs on a baking pan. Bake for 25 minutes or until golden brown and firm to touch. Allow to cool for 10 minutes before slicing them diagonally into 1/2-3/4 inch thickness with a serrated knife. Place the slices cut side up back onto the baking pan.
Bake for 10 minutes and turn over the biscotti. Bake for another 10 minutes until the slices are lightly toasted. Remove from the oven. Allow them to cool for 5 minutes before transferring to the wire rack to cool completely.
Chocolate Dip
Dip the biscotti into melted chocolate and sprinkle with the remaining toasted almonds.