Preheat oven to 350°F. Line a baking sheet with parchment paper or use a silicone mat. 

Cut cauliflower into quarters. Remove the core, and break the remaining pieces into florets. Cut the larger florets in half to ensure that all pieces are approximately the same size.

Toss cauliflower with olive oil in a large bowl. 

Place cauliflower pieces on a baking sheet and roast until tender and just starting to brown, 20 to 25 minutes. Let cool at room temperature.

Once the cauliflower cools add all ingredients to a food processor. Process until combined, scraping down the sides of the bowl as needed. 

Transfer into a bowl and drizzle with olive oil. Garnish with parsley if desired.