Combine the cream cheese, shredded Cheddar, and diced jalapenos with a mixer. Chill the cheese mixture in the refrigerator for 30 minutes.
Make a paste by stirring the flour and water together. This will be used to glue the spring roll wrapper closed.
Divide the cheese mixture into 8 even pieces. With your hands, roll each piece into a log shape then wrap each in a spring roll wrapper. To roll in the wrapper, lay a wrapper on the counter with 1 corner pointing toward you. Place the cheese log near that corner. Wrap that corner around the cheese and roll the whole thing up until the cheese log is level with the 2-sided corner. At this point fold both side corners to the center. Continue to roll it up until almost to the final corner. Use your finger to paint some of the flour paste on that corner. Finish rolling to seal the corner to the roll. Let spring rolls rest for about 10 minutes while the oil is heating.
Fill a large heavy Dutch oven no more than halfway full with peanut oil. Heat the oil to 375 degrees F.
When the oil reaches temperature, gently slip a few of the spring rolls in the oil. Fry for about 2 minutes or until the wrapper is golden brown. When the spring rolls are done, lift them out of the oil with a slotted spoon or spatula and let them drain on a cooling rack over a sheet pan. Repeat with remaining spring rolls. Allow to cool for 10 minutes before eating.