Heat sunflower oil in a deep-fat fryer or a Dutch oven to 350 degrees F.
Cut the top and bottom off the pineapple, then quarter it vertically. Trim the woody core off each segment, and then lay it skin side down, and slice the flesh in half lengthwise, stopping when you feel the skin. Then cut it across into slices and run the knife between the flesh of the fruit and the outer husk. The pineapple pieces should come out easily. Squeeze the outer skin of the pineapple over the cut fruit to get every last bit of juice.
In a large bowl, add 1 cup of flour. Gently whisk in 3/4 cup of soda water, if the batter is too thick, add the 1/4 cup. It should be able to coat the candy bar easily. Submerge each chocolate coconut bar in the batter and place it right into the hot oil either with your fingers or tongs, allowing it to fry for about 3 minutes or until the batter is puffed up and golden brown. Using tongs, remove the battered chocolate coconut bars and place them on a paper towel lined plate. Transfer them to a plate aside the pineapple pieces, enjoy immediately.
Recipe courtesy of Nigella Lawson 2007