Preheat the oven to 175 degrees C. In a medium saucepan over low heat, melt the caramel and cream together, stirring until smooth.
In a medium bowl, combine flour, oatmeal, sugar, soda and salt. Add melted butter, mix everything well. Put half of the mixture in a baking dish and tamp well. Bake for 8 minutes.
Remove from the oven and sprinkle with chocolate chips and walnuts. Pour the caramel mixture onto the top and then the remaining crumb. Return to oven and bake for another 12 minutes, cut into squares while warm.