Smashburger, a Denver-based burger chain, plans to open its first California store March 31 in Citrus Heights. It’s the first of five Smashburgers scheduled to open in Sacramento in the next two years. Smashburger, which calls itself a “fast-casual better burger” restaurant, serves Certified Angus Beef burgers and Häagen-Daz milkshakes. The chain’s name comes from the way the burgers are cooked: A ball of meat is placed on a hot grill, then smashed. The first Smashburger location, at 5500 Sunrise Blvd., will be followed by stores in Folsom and Roseville.