Lay two of the bread slices out onto the counter and lay the other two over the first two so that they overlap slightly.
Using a rolling pin or wine bottle, gently flatten the slices of bread and press them together at the seam.
Gently spread your favorite spread evenly over both of the bread pieces and lay a whole banana in the middle of each. Carefully roll up the bread around the banana, bringing one long end over to the other.
Slice each log into 6 pieces that are 1-1 1/2 thick and serve.