Add brown sugar and granulated sugar, salt and baking soda.
Beat until combined, add in egg and vanilla.
Add in flour, toffee bits and ground almonds.
Divide dough in half. Shape into a 10 inch long roll and wrap in plastic wrap. Refrigerate for 6 hours (or 1 hour in the freezer). The dough needs to be firm enough to slice.
Preheat oven to 375 degrees.
Cut rolls into 1/4 inch slices and place on ungreased cookie sheet.
Bake 7-8 minutes or until edges are firm and light brown. Cool on rack.
Browned Butter Icing:
In a small pan melt 4 Tbsp. butter over medium heat until the butter turns light brown.
Stir frequently.
Remove from heat and add in 3 cups powdered sugar and 2 tsp vanilla.
Add enough milk (1-2 Tbsp) to make the icing spreading consistency.
To Toast Nuts:
To Toast in the oven: Heat oven to 300 degrees and spread nuts out in a single layer on a cookie sheet. Bake for 10-15 minutes or until they begin to turn golden brown.
To Toast on the stove top: Place them in a frying pan over medium heat in a single layer and stir until they begin to turn golden brown. Remove from pan and cool on a plate.
Grind them in your food processor or blender.
Notes
Chill the dough: Place it in the refrigerator for about six hours, wrapped in plastic wrap or wax paper but if you are rushed for time, you can place the dough in the freezer for one hour.Parchment Paper: I always using parchment paper on my baking sheets.Nuts: I like my nuts chopped fine so I used a food processor but if you like larger pieces, just give them a rough chop with a knife.Toffee Bits: I like the toffee bits that come covered in chocolate but you can also used the ones without chocolate.