Grease a 9×13″ baking sheet with butter.
Melt the butter in a 2 quart saucepan over low heat. In a separate bowl, combine the corn syrup and water and stir to dissolve fully.
Turn the heat to medium and add the sugar, stirring constantly until sugar fully dissolves, about 3-5 minutes. Add the corn syrup and water mixture.
Turn the heat to medium high and continue stirring the mixture constantly until it reaches a temperature of 300 degrees.
Remove from heat and quickly mix in the chopped almonds. Pour the candy mixture on the greased baking sheet and let it spread out. It should be about 1/4″ thick . Pick up the pan and shake gently back and forth to help the mixture more evenly.
Before it starts to cool, sprinkle the top with the chocolate chips and let them melt for 2-3 minutes. Spread the melted chocolate with a knife in an even layer over the buttercrunch. OPTIONAL: Sprinkle the top with about 1/2 tsp. of coarse sea salt. Then sprinkle the top with the ground nuts.
Let the chocolate and butter toffee cool and use a knife to break into pieces. To speed up the cooling, I typically place it in the fridge for 15-20 minutes. Just be careful not to leave it in there too long or the chocolate will become too hard and separate from the toffee.
Store in an airtight container on the counter or in the fridge. It should be a cool place.