Preheat oven to 180 degrees C. Grease and flour a 20x30cm cake tin.
Base Cake: In a large bowl, combine flour, salt, bicarb soda and baking powder. Add sugar, butter, eggs and vanilla, then mix well. Reserve 2/3 cup of batter for filling, spread the remaining batter in the prepared cake tin. Bake the cake base for 15 minutes.
Top Cake: In a saucepan, heat golden syrup, sugar and butter until melted and hot. Remove from heat and beat in the reserved 2/3 cup of cake batter. Stir in 3 eggs and add pecans. Pour on top of cake. Return to oven and bake an additional 40 minutes.