Step 1

Combine the canned tomatoes, water, salt, onion powder and garlic powder in a medium saucepan.

Step 2

Bring to a boil over medium-high heat and then simmer for 2 minutes.

Step 3

Remove from the heat and puree with an immersion blender until smooth (or transfer to a traditional blender and blend, then return blended soup to the pan.)

Step 4

Return to the stove and add the butter and mascarpone cheese to the soup.

Step 5

Stir over low heat until melted and creamy – about 2 minutes.

Step 6

Remove from the heat and stir in the sweetener, apple cider vinegar, dried basil, and pesto.

Step 7

Serve warm.

Step 8

Store any leftovers in a covered container in the refrigerator for up to 5 days, or in the freezer for up to three months.