Preheat oven to 350 degrees F (175 degrees C) In a small saucepan, melt butter and cook over low heat until browned. Remove from heat immediately to a medium bowl.
Mix the brown sugar and bourbon into the butter until smooth. Beat in the eggs one at a time, and stir in the vanilla. Combine the flour, baking powder and salt; stir into the egg mixture. Mix in the almonds and butterscotch chips. Form into 2 long loaves and place onto a cookie sheet.
Bake for 15 to 20 minutes in the preheated oven, or until firm. Allow the loaves to cool on the baking sheet. When they are cool enough to handle, slice diagonally into 1/2 inch slices. Return the slices cut side up to the baking sheet and bake for 15 to 20 additional minutes, turning once, until toasted on both sides. Cool completely and store in an airtight container at room temperature.