In a heavy-bottomed, four-quart saucepan over medium-high heat, combine the tomatoes, granulated sugar, brown sugar, lemon juice, salt, cumin and cinnamon.
Bring the mixture to a boil, stirring occasionally.
Decrease the heat to low and cook, uncovered, stirring continually to prevent scorching, until the mixture has reduced by half, 40 to 45 minutes.
Remove from the heat and let cool completely before using.
Transfer to an airtight container and store in the refrigerator for up to two weeks or the freezer for up to two months.
