Rotational Motion

The position of a particle of mass 1 kg at time $t$ is given by $\mathbf{r} = t\,\hat{i} + \hat{j} + 2t^2\,\hat{k}$, where $t$ is in seconds and the coefficients have the proper units for $\mathbf{r}$ to be in metres. What is the component of the angular momentum (with respect to the origin) in kg m$^2$s$^{-1}$ along the vector $(\hat{i} + \hat{j})$?