1. Preheat the oven to 190°C.
2. Place the bacon on a baking tray lined with baking paper and place in the oven for 10 minutes. Remove the bacon and pat it dry with some kitchen roll. When cool enough to handle, cut the slices into small pieces.
3. Sift the flour, bicarbonate of soda, baking powder and salt into a bowl and set to one side.
4. Using a mixer fitted with the paddle attachment, cream the butter and sugar together on medium speed until the mixture becomes light and fluffy (approximately 5 minutes).
5. Reduce the speed of the mixer to low and add the eggs, one at a time, and continue to mix until well incorporated.
6. Add the sifted flour to the creamed butter, sugar and egg mixture. Continue to mix for 3-5 minutes until the dry ingredients are thoroughly incorporated and a dough is formed. Add the banana and bacon and continue to mix for 2 minutes.
7. Using an ice-cream scoop, portion the dough into balls (approximately 40g per ball). Place them on a parchment-lined baking tray, roughly 10 cm apart.
8. Place the tray in the oven for 8-10 minutes or until the cookies are golden brown and crispy at the edges. Remove the tray from the oven and allow the cookies to rest on the tray for a few minutes before placing on a cooling rack.
The cookies will keep for up to 5 days in an airtight tin.