In a large pot, salt water and bring to a boil.

Place all of the Pesto ingredients except for the avocado into a food processor. Pulse. Once the basil and nuts are chopped small, blend in the avocado.

When the water is boiling, add pasta.

While pasta is cooking, add the ingredients for the whipped ricotta into the base of a stand mixer fitted with the whisk attachment. Whip on high.

When pasta is done, reserve 1 cup of pasta water.

(Hint: I didn't actually use the water in this recipe but it's good practice to do this every time you make a pasta with sauce so you can easily fix the consistency of the sauce to your liking.

After draining pasta, return to the pot and add butter, cream and brie. Toss pasta to melt the cheese and make a sauce. Add the pesto and toss until the pasta is coated.

Serve with a dollop of whipped ricotta, chopped walnuts, and some lemon zest.