Preheat oven to 350º F. Spread almonds out on a small baking sheet. Toast in the oven for about 10 minutes, or until almonds become fragrant and are toasted. Remove from oven immediately and pour almonds into a separate bowl to cool.

Prepare a large bowl of ice water and a pan of boiling water. While almonds are in the oven, blanch basil leaves by immersing them a few at a time into the pan of boiling water for about 15 seconds until they turn bright green. Immediately remove them from the boiling water and plunge them into the bowl of ice water. When cool lay them out on the paper towel or clean dish towel to absorb any extra water. Gently pat dry.

Toss almonds, basil leaves, and garlic into a food processor and process, or blend, until almonds are finely chopped and interspersed with the basil and garlic. Add olive oil, and salt and pepper (if using) and process till incorporated into the basil and almond mixture.

Add parmesan cheese and blend to desired consistency. If freezing, do not add parmesan cheese until ready to use.

Keep refrigerated.